Title:
ELECTRONIC MUSICAL INSTRUMENT CAPABLE OF TRANSPOSITION
United States Patent 3877337
Abstract:
An electronic musical instrument capable of transposition has a high frequency oscillator provided on its output side with an octave frequency divider comprising 12 counter circuits to generate 12 tone signals based on a twelve tempered scale. These tone signals are respectively frequency-divided by respective pluralities of counter circuits to obtain a plurality of octave tone signals. An oscillator for transposition comprising a plurality of counter circuits is provided and the output terminals of these counter circuits are selectively connected to an input terminal of the octave frequency divider such that the oscillation frequency generated from the high frequency oscillator is added to the oscillation frequency generated from the transposition oscillation to produce an input frequency for the octave frequency divider.
US Patent References:
Transposition apparatus for electrical musical instrument
Bode - March 1962 - 3023659
Electronic musical instrument
Freeman - February 1966 - 3236931
Electrically operated music display and cuing apparatus
Weitzner - April 1968 - 3379087
ELECTRONIC MUSICAL SCALE GENERATOR EMPLOYING A SINGLE MASTER OSCILLATOR
Reyers - June 1971 - 3590131
DIGITAL ELECTRONIC KEYBOARD INSTRUMENT WITH AUTOMATIC TRANSPOSITION
Deutsch - October 1971 - 3610800
Transposition apparatus for electrical musical instrument
Bode - March 1962 - 3023659
Electronic musical instrument
Freeman - February 1966 - 3236931
Electrically operated music display and cuing apparatus
Weitzner - April 1968 - 3379087
ELECTRONIC MUSICAL SCALE GENERATOR EMPLOYING A SINGLE MASTER OSCILLATOR
Reyers - June 1971 - 3590131
DIGITAL ELECTRONIC KEYBOARD INSTRUMENT WITH AUTOMATIC TRANSPOSITION
Deutsch - October 1971 - 3610800
Inventors:
Obayashi, Nobuharu (Shizuoka-ken, JA)
Sakashita, Tetsuzi (Hammatsu, JA)
Sakashita, Tetsuzi (Hammatsu, JA)
Application Number:
05/352627
Publication Date:
04/15/1975
Filing Date:
04/19/1973
View Patent Images:
Export Citation:
Assignee:
Kabushiki Kaisha Kawai Gakki Seisakusho (Shizuoka-ken, JA)
Primary Class:
Other Classes:
84/445, 984/381, 84/648, 984/338, 84/685, 84/657
International Classes:
G10H1/20; G10H5/06; G10H5/00; G10H1/00; G10H5/06
Field of Search:
84/1.01,1.22,1.23,445,1.24
US Patent References:
Primary Examiner:
Wilkinson, Richard B.
Assistant Examiner:
Witkowski, Stanley J.
Attorney, Agent or Firm:
Waters, Roditi, Schwartz & Nissen
Claims:
What is claimed is
1. An electronic musical instrument capable of transposition comprising a high frequency oscillator having an output side, an octave frequency divider including twelve counter circuits to generate twelve tone signals, a transposition oscillator including a plurality of counter circuits coupled between the output side of said oscillator and said divider, means to control the addition of the frequency of the output of said high frequency oscillator to the frequency of the output of the transposition oscillator to generate an input frequency for the octave frequency divider, said means including a NOT circuit coupled between said oscillators and an OR circuit coupled between said high frequency oscillator and divider, and a selector switch between the transposition oscillator and said OR circuit.
2. An instrument as claimed in claim 1 comprising differentiation circuits coupled between said OR circuit and said high frequency oscillator and switch.
3. An instrument as claimed in claim 1 comprising frequency divider means coupled to said high frequency oscillator and a change-over switch coupling said frequency divider means to said NOT circuit and OR circuit.
4. An electronic musical instrument capable of transposition comprising a high frequency oscillator having an output side, an octave frequency divider including twelve counter circuits to generate twelve tone signals, a transposition oscillator includiing a plurality of counter circuits coupled between the output side of said oscillator and said divider, means to control the addition of the frequency of the output of said high frequency oscillator to the frequency of the output of the transposition oscillator to generate an input frequency for the octave frequency divider, said means including a binary circuit between the high frequency oscillator and the transposition oscillator and divider and an OR circuit coupling said high frequency oscillator and said transposition oscillator to said divider.
1. An electronic musical instrument capable of transposition comprising a high frequency oscillator having an output side, an octave frequency divider including twelve counter circuits to generate twelve tone signals, a transposition oscillator including a plurality of counter circuits coupled between the output side of said oscillator and said divider, means to control the addition of the frequency of the output of said high frequency oscillator to the frequency of the output of the transposition oscillator to generate an input frequency for the octave frequency divider, said means including a NOT circuit coupled between said oscillators and an OR circuit coupled between said high frequency oscillator and divider, and a selector switch between the transposition oscillator and said OR circuit.
2. An instrument as claimed in claim 1 comprising differentiation circuits coupled between said OR circuit and said high frequency oscillator and switch.
3. An instrument as claimed in claim 1 comprising frequency divider means coupled to said high frequency oscillator and a change-over switch coupling said frequency divider means to said NOT circuit and OR circuit.
4. An electronic musical instrument capable of transposition comprising a high frequency oscillator having an output side, an octave frequency divider including twelve counter circuits to generate twelve tone signals, a transposition oscillator includiing a plurality of counter circuits coupled between the output side of said oscillator and said divider, means to control the addition of the frequency of the output of said high frequency oscillator to the frequency of the output of the transposition oscillator to generate an input frequency for the octave frequency divider, said means including a binary circuit between the high frequency oscillator and the transposition oscillator and divider and an OR circuit coupling said high frequency oscillator and said transposition oscillator to said divider.
Description:
FIELD OF INVENTION
This invention relates to an electronic musical instrument capable of transposition.
BACKGROUND
In an ordinary keyed instrument, natural keys are disposed for natural tones and chromatic keys are disposed for their derivative tones. Accordingly, when flat families or sharp families are played in this kind of instrument, transposed tones require the use of chromatic keys. For example, C, D, E, F, G, A, B, C in the case of C major are played by pressing natural keys. However, D major begins with the D tone. Accordingly, natural keys and chromatic keys must be pressed. Thus, the operation of chromatic keys is required for transposition and this applies also to the case of all electronic musical instruments. Thus, playing with transposition is very difficult for a beginner.
SUMMARY OF INVENTION
The present invention relates to an electronic musical instrument which, in view of the foregoing fact, is so designed that sharp families and flat families can be played by using natural keys only in a manner similar to the case of C major, through shifting of frequencies of sound sources associated with and corresponding to the respective keys, without using chromatic keys, and such that any music can be readily played by means of a switch.
The instrument is characterized by the following: in an electronic musical instrument capable of transposition a high frequency oscillator is provided on its output side with an octave frequency divider comprising twelve counter circuits to generate twelve tone signals based on a twelve tempered scale. These tone signals are respectively frequency divided by respective pluralities of counter circuits to obtain a plurality of octave tone signals. The instrument is characterized in that an oscillator for transposition comprising a plurality of counter circuits is provided, and the output terminals of these counter circuits are selectively connected to the input terminal of the octave frequency divider such that the oscillation frequency generated from the high frequency oscillator is added to the oscillation frequency generated from the transposition oscillator so as to produce an input frequency for the octave frequency divider.
BRIEF DESCRIPTION OF DRAWING
Examples of this invention will next be explained with reference to the accompanying drawings in which:
FIG. 1 is a diagram showing the relationship between keys and tones;
FIGS. 2 and 3 are each a block diagram showing the frequency dividing system of an octave frequency divider;
FIG. 4 is a block diagram of one example of this invention;
FIG. 5 is a diagram showing a wave form at each portion thereof; and
FIGS. 6 and 7 are each a block diagram showing another example of this invention.
DETAILED DESCRIPTION
As shown in FIG. 1, C, D, E, F, G, A, B and C in the case of C major are played by pressing the natural keys K1, K3, K5, K6, K8, K10 and K12. However in the case of D major, this begins with the D tone. Accordingly, the natural keys K3, K5, chromatic key K7, natural keys K8, K10, K12 and K13, chromatic key K14 and natural key K15 must be employed. Thus, the operation of chromatic keys is required for the transposition and this applies to the case of all electronic musical instruments. Thus, playing with transposition can be very difficult for the beginner.
As for systems employing an octave frequency divider, there are two such systems. FIG. 2 shows one system with octave frequency divider 20 which comprises twelve counter circuits (20-1).....(20-12) connected in series with one another. The frequency dividing ratio of each thereof is 196/185. If it is assumed that a frequency of 8372.02 Hz is generated by the first counter circuit (20-1), the oscillation frequency fm of a high frequency oscillator 10 connected to the input terminal of the octave frequency divider 20 becomes 196/185 times said frequency, that is, 8869.84 Hz. Thus, the oscillation frequencies obtained at output terminals (20-1a).....(20-12a) of the counter circuits (20-1).....(20-12) become those shown in FIG. 2. The tone signals of the respective frequencies are as shown in parentheses. Though not illustrated, these oscillation frequencies are each further frequency-divided by each of a respective plurality of counter circuits, for example, into 7 stages if it is intended to cover 7 octaves of a whole piano.
FIG. 3 shows the other system of octave frequency divider 20'. It comprises twelve counter circuits (20'-1).....(12'-12) connected in parallel with one another to a common high frequency oscillator 10'. The frequency dividing ratios thereof are 1/239, 1/253......1/451, respectively, as shown in FIG. 3. If it is assumed that 8372.02 Hz is generated by the first counter circuit (20'-1), the oscillation frequency fm' of the high frequency oscillator 10' is 239 times said frequency, that is, 2.00024 MHz. Thus, the oscillation frequencies obtained at output terminals (20'-1a).....(20'-12a) of the counter circuits (20'-1).....(20'12) become nearly equal to those in the case shown in FIG. 2.
FIG. 4 shows one example of this invention. An output terminal of a high frequency oscillator 10' is connected to an octave frequency divider 20' through an OR circuit 30 and is connected, in parallel therewith, through a NOT circuit 40 (i.e., a circuit which changes a 0 to a 1 and vice versa) to an oscillator 50, for transposition, comprising a plurality of counter circuits (50-2).....(50-12). It is so arranged that output terminals of transposition oscillator are selectively connected to the OR circuit 30 through a change-over switch 60. The change-over switch 60 comprises a stationary contact (60-1) positioned at a zero position and not connected to the transposition oscillation 50, a plurality of stationary contacts (60-2).....(60-12) connected to the respective counter circuits (50-2).....(50-12), and movable contact connected to the OR circuit 30.
The oscillation frequency of the high frequency oscillator 10' is 2.00024 MHz and the wave form thereof is as shown in FIG. 5 (a). This wave form is then differentiated by differentiation circuit D2 (FIG. 4) into the wave form shown in FIG. 5 (b) and is applied to the octave frequency divider 20' through the OR circuit 30. Also, the output wave form shown in FIG. 5 (a) of the high frequency oscillator 10' is inverted by the NOT circuit 40 as shown in FIG. 5 (c) and is differentiated by differentiation circuit D2 (FIG. 4) as shown in FIG. 5 (d) and is applied to the transposition oscillator 50.
The oscillation frequencies generated at the respective counter circuits (50-2).....(50-12) of the transposition oscillator 50 are shown in Table 1 below.
TABLE 1 ______________________________________ Counter cir- Oscillation Total fre- Tone cuit number frequency MHz quency MHz signal ______________________________________ 1 1 2.00024 C 2 50 - 2 0.11717 2.11741 C♯(D♭) 3 50 - 3 0.24055 2.24079 D 4 50 - 4 0.37661 2.37685 D♯(E♭) 5 50 - 5 0.51889 2.51913 E 6 50 - 6 0.66953 2.66977 F 7 50 - 7 0.82875 2.82899 F♯(G♭) 8 50 - 8 0.99593 2.99617 G 9 50 - 9 1.17169 3.17192 G♯(A♭) 10 50 - 10 1.36418 3.36442 A 11 50 - 11 1.56504 3.56528 A♯(B♭) 12 50 - 12 1.77427 3.77451 B ______________________________________
As clear from Table 1, the dividing ratios of counter circuits (50-2)...(50-12) are as follows:
50 - 2 2.00024/0.11717 50 - 3 2.00024/0.24055 50 - 4 2.00024/0.37661 50 - 5 2.00024/0.51889 . . .
When the movable contact 60a is set to the stationary contact (60-1), the oscillation frequency 2.00024 MHz itself of the high frequency oscillator 10' becomes an input for the octave frequency divider 20', and output frequencies as shown in Table 2, column (I) are obtained at its respective output terminals. The tone signals corresponding to the respective frequencies are as shown on the right hand side thereof. This is C major, and playing can be carried out by using natural keys only.
If, next, the movable contact 60a is connected to the stationary contact (60-2), the oscillation frequency 0.11717 MHz of the counter circuit (50-2) is added to the oscillation frequency 2.00024 MHz of the high frequency oscillator 10'. This condition is such that the wave form (FIG. 5 (c) inverted by the NOT circuit 40 is used as the input for the transposition oscillator 50, and the output thereof is differentiated (FIG. 5 (d)) and is properly interposed through the OR circuit 30 in the oscillation frequency of the high frequency oscillator 10' (FIG. 5 (e)).
Thus, the input frequency for the octave frequency divider 20' becomes 2.11741 MHz and, accordingly, the output frequencies of the octave frequency divider become those shown in Table 2, column (II). The tone signals are as shown on the right hand side thereof. This is a C♯ and shows that it is transposed to the higher side by one interval. Accordingly, playing of C♯ major can be easily effected by operating only natural keys in almost the same manner as in the case of C major, without using chromatic keys.
If, next, the movable contact 60a is connected to the stationary contact (60-3), the oscillation frequency 0.24055 MHz of the counter circuit (50-3) is added to the oscillation frequency 2.00024 MHz of the high frequency oscillator 10' and it becomes 2.24079 MHz. The respective oscillation frequencies of the octave frequency divider 20' becomes those shown in Table 2, column (III), and the tone signal thereof is D and this shows that it is further transposed to the higher side by one interval. Accordingly, playing of D major can be effected by the operation of only natural keys. Thus, any desired transposition can be effected by that the oscillation frequencies of the counter circuits (50-2).....(50-12) of the transposition oscillator 50 are selectively added to the oscillation frequency of the high oscillator 10', and thereby the playing of any desired music with sharps or flats becomes possible by using only natural keys.
TABLE 2 ____________________________________________________________ ______________ Counter circuit (I) C major (II) C major (III) D major number of octave frequency Output fre- Tone Output fre- Tone Output fre- Tone divider quency Hz signal quency Hz signal quency Hz signal ____________________________________________________________ ______________ 1 20' - 1 8372.02 C 8869.84 C♯ 9397.21 D 2 20' - 1 7902.13 B 8372.02 C 8869.84 C♯ 3 20' - 3 7458.62 A♯ 7902.13 B 8372.02 C 4 20' - 4 7040.00 A 7458.62 A♯ 7902.13 B 5 20' - 5 6644.88 C♯ 7040.00 A 7458.62 A♯ 6 20' - 6 6271.93 G 6644.88 G♯ 7040.00 A 7 20' - 7 5919.91 F♯ 6271.93 G 6644.88 G♯ 8 20' - 8 5587.65 F 5919.91 F♯ 6271.93 G 9 20' - 9 5274.04 E 5587.65 F 5919.91 F♯ 10 20' - 10 4978.03 D♯ 5274.04 E 5587.65 F 11 20' - 11 4698.64 D 4978.03 D♯ 5274.04 E 12 20' - 12 4434.94 C♯ 4698.64 D 4978.03 D♯ Input frequency 2.00024 MHz 2.11741 MHz 2.24079 MHz Contact number of 60 - 0 60 - 2 60 - 3 change-over switch ____________________________________________________________ ______________
The above is the case where transposition is to the higher side. As shown in FIG. 6, the high frequency oscillator 10' is provided on its output side with a frequency divider 70 comprising a plurality of counter circuits, so that the oscillation frequencies thereof are lowered by steps at each counter circuit. If the output terminals thereof are selectively connected to the OR circuit 30 and the NOT circuit 40 through a change-over switch 80, a transposition to the lower side can be easily effected by selective connection of the change-over switch 80 and selective connection of the change-over switch 60. Additionally, movement of an octave becomes possible by that the frequency dividing ratio of each counter circuit of the frequency divider 70 is designed to be 1/2. If, under this condition, the oscillation frequency of the high frequency oscillator 10 is made higher by several octaves, movement of an octave either to the higher side or the lower side becomes possible by selective connection of the change-over switch 80. Accordingly, a player can play any octave at a predetermined position, without especially moving his position.
FIG. 7 shows the case where the NOT circuit in FIGS. 4 and 6 is omitted. In this case, the oscillation frequency of the high frequency oscillator 10' is doubled to be 4.00048 MHz and this frequency is made to be 1/2 through a binary circuit 90. At the same time, positive and negative wave forms as shown in FIGS. 5 (a) and (c) are taken from the binary circuit 90. Thus, this only slightly different from the case of FIGS. 4 and 6.
The above explanation has been given with reference to the second frequency dividing system of an octave frequency divider, but this is similar also in the case of the first system except only that the oscillation frequencies of the high frequency oscillator 10 and the transposition oscillator become smaller.
Thus, according to this invention, the oscillation frequency of the high frequency oscillator is properly added to any of the oscillation frequencies of the transposition oscillator comprising the plurality of counter circuits so as to produce an input for the octave frequency divider so that, by means of selecting the adding frequency, and desired transposition can be effected. Accordingly, the playing of any desired music with sharps or flats can be effected by a player as long as he can play in C major.
This invention relates to an electronic musical instrument capable of transposition.
BACKGROUND
In an ordinary keyed instrument, natural keys are disposed for natural tones and chromatic keys are disposed for their derivative tones. Accordingly, when flat families or sharp families are played in this kind of instrument, transposed tones require the use of chromatic keys. For example, C, D, E, F, G, A, B, C in the case of C major are played by pressing natural keys. However, D major begins with the D tone. Accordingly, natural keys and chromatic keys must be pressed. Thus, the operation of chromatic keys is required for transposition and this applies also to the case of all electronic musical instruments. Thus, playing with transposition is very difficult for a beginner.
SUMMARY OF INVENTION
The present invention relates to an electronic musical instrument which, in view of the foregoing fact, is so designed that sharp families and flat families can be played by using natural keys only in a manner similar to the case of C major, through shifting of frequencies of sound sources associated with and corresponding to the respective keys, without using chromatic keys, and such that any music can be readily played by means of a switch.
The instrument is characterized by the following: in an electronic musical instrument capable of transposition a high frequency oscillator is provided on its output side with an octave frequency divider comprising twelve counter circuits to generate twelve tone signals based on a twelve tempered scale. These tone signals are respectively frequency divided by respective pluralities of counter circuits to obtain a plurality of octave tone signals. The instrument is characterized in that an oscillator for transposition comprising a plurality of counter circuits is provided, and the output terminals of these counter circuits are selectively connected to the input terminal of the octave frequency divider such that the oscillation frequency generated from the high frequency oscillator is added to the oscillation frequency generated from the transposition oscillator so as to produce an input frequency for the octave frequency divider.
BRIEF DESCRIPTION OF DRAWING
Examples of this invention will next be explained with reference to the accompanying drawings in which:
FIG. 1 is a diagram showing the relationship between keys and tones;
FIGS. 2 and 3 are each a block diagram showing the frequency dividing system of an octave frequency divider;
FIG. 4 is a block diagram of one example of this invention;
FIG. 5 is a diagram showing a wave form at each portion thereof; and
FIGS. 6 and 7 are each a block diagram showing another example of this invention.
DETAILED DESCRIPTION
As shown in FIG. 1, C, D, E, F, G, A, B and C in the case of C major are played by pressing the natural keys K1, K3, K5, K6, K8, K10 and K12. However in the case of D major, this begins with the D tone. Accordingly, the natural keys K3, K5, chromatic key K7, natural keys K8, K10, K12 and K13, chromatic key K14 and natural key K15 must be employed. Thus, the operation of chromatic keys is required for the transposition and this applies to the case of all electronic musical instruments. Thus, playing with transposition can be very difficult for the beginner.
As for systems employing an octave frequency divider, there are two such systems. FIG. 2 shows one system with octave frequency divider 20 which comprises twelve counter circuits (20-1).....(20-12) connected in series with one another. The frequency dividing ratio of each thereof is 196/185. If it is assumed that a frequency of 8372.02 Hz is generated by the first counter circuit (20-1), the oscillation frequency fm of a high frequency oscillator 10 connected to the input terminal of the octave frequency divider 20 becomes 196/185 times said frequency, that is, 8869.84 Hz. Thus, the oscillation frequencies obtained at output terminals (20-1a).....(20-12a) of the counter circuits (20-1).....(20-12) become those shown in FIG. 2. The tone signals of the respective frequencies are as shown in parentheses. Though not illustrated, these oscillation frequencies are each further frequency-divided by each of a respective plurality of counter circuits, for example, into 7 stages if it is intended to cover 7 octaves of a whole piano.
FIG. 3 shows the other system of octave frequency divider 20'. It comprises twelve counter circuits (20'-1).....(12'-12) connected in parallel with one another to a common high frequency oscillator 10'. The frequency dividing ratios thereof are 1/239, 1/253......1/451, respectively, as shown in FIG. 3. If it is assumed that 8372.02 Hz is generated by the first counter circuit (20'-1), the oscillation frequency fm' of the high frequency oscillator 10' is 239 times said frequency, that is, 2.00024 MHz. Thus, the oscillation frequencies obtained at output terminals (20'-1a).....(20'-12a) of the counter circuits (20'-1).....(20'12) become nearly equal to those in the case shown in FIG. 2.
FIG. 4 shows one example of this invention. An output terminal of a high frequency oscillator 10' is connected to an octave frequency divider 20' through an OR circuit 30 and is connected, in parallel therewith, through a NOT circuit 40 (i.e., a circuit which changes a 0 to a 1 and vice versa) to an oscillator 50, for transposition, comprising a plurality of counter circuits (50-2).....(50-12). It is so arranged that output terminals of transposition oscillator are selectively connected to the OR circuit 30 through a change-over switch 60. The change-over switch 60 comprises a stationary contact (60-1) positioned at a zero position and not connected to the transposition oscillation 50, a plurality of stationary contacts (60-2).....(60-12) connected to the respective counter circuits (50-2).....(50-12), and movable contact connected to the OR circuit 30.
The oscillation frequency of the high frequency oscillator 10' is 2.00024 MHz and the wave form thereof is as shown in FIG. 5 (a). This wave form is then differentiated by differentiation circuit D2 (FIG. 4) into the wave form shown in FIG. 5 (b) and is applied to the octave frequency divider 20' through the OR circuit 30. Also, the output wave form shown in FIG. 5 (a) of the high frequency oscillator 10' is inverted by the NOT circuit 40 as shown in FIG. 5 (c) and is differentiated by differentiation circuit D2 (FIG. 4) as shown in FIG. 5 (d) and is applied to the transposition oscillator 50.
The oscillation frequencies generated at the respective counter circuits (50-2).....(50-12) of the transposition oscillator 50 are shown in Table 1 below.
TABLE 1 ______________________________________ Counter cir- Oscillation Total fre- Tone cuit number frequency MHz quency MHz signal ______________________________________ 1 1 2.00024 C 2 50 - 2 0.11717 2.11741 C♯(D♭) 3 50 - 3 0.24055 2.24079 D 4 50 - 4 0.37661 2.37685 D♯(E♭) 5 50 - 5 0.51889 2.51913 E 6 50 - 6 0.66953 2.66977 F 7 50 - 7 0.82875 2.82899 F♯(G♭) 8 50 - 8 0.99593 2.99617 G 9 50 - 9 1.17169 3.17192 G♯(A♭) 10 50 - 10 1.36418 3.36442 A 11 50 - 11 1.56504 3.56528 A♯(B♭) 12 50 - 12 1.77427 3.77451 B ______________________________________
As clear from Table 1, the dividing ratios of counter circuits (50-2)...(50-12) are as follows:
50 - 2 2.00024/0.11717 50 - 3 2.00024/0.24055 50 - 4 2.00024/0.37661 50 - 5 2.00024/0.51889 . . .
When the movable contact 60a is set to the stationary contact (60-1), the oscillation frequency 2.00024 MHz itself of the high frequency oscillator 10' becomes an input for the octave frequency divider 20', and output frequencies as shown in Table 2, column (I) are obtained at its respective output terminals. The tone signals corresponding to the respective frequencies are as shown on the right hand side thereof. This is C major, and playing can be carried out by using natural keys only.
If, next, the movable contact 60a is connected to the stationary contact (60-2), the oscillation frequency 0.11717 MHz of the counter circuit (50-2) is added to the oscillation frequency 2.00024 MHz of the high frequency oscillator 10'. This condition is such that the wave form (FIG. 5 (c) inverted by the NOT circuit 40 is used as the input for the transposition oscillator 50, and the output thereof is differentiated (FIG. 5 (d)) and is properly interposed through the OR circuit 30 in the oscillation frequency of the high frequency oscillator 10' (FIG. 5 (e)).
Thus, the input frequency for the octave frequency divider 20' becomes 2.11741 MHz and, accordingly, the output frequencies of the octave frequency divider become those shown in Table 2, column (II). The tone signals are as shown on the right hand side thereof. This is a C♯ and shows that it is transposed to the higher side by one interval. Accordingly, playing of C♯ major can be easily effected by operating only natural keys in almost the same manner as in the case of C major, without using chromatic keys.
If, next, the movable contact 60a is connected to the stationary contact (60-3), the oscillation frequency 0.24055 MHz of the counter circuit (50-3) is added to the oscillation frequency 2.00024 MHz of the high frequency oscillator 10' and it becomes 2.24079 MHz. The respective oscillation frequencies of the octave frequency divider 20' becomes those shown in Table 2, column (III), and the tone signal thereof is D and this shows that it is further transposed to the higher side by one interval. Accordingly, playing of D major can be effected by the operation of only natural keys. Thus, any desired transposition can be effected by that the oscillation frequencies of the counter circuits (50-2).....(50-12) of the transposition oscillator 50 are selectively added to the oscillation frequency of the high oscillator 10', and thereby the playing of any desired music with sharps or flats becomes possible by using only natural keys.
TABLE 2 ____________________________________________________________ ______________ Counter circuit (I) C major (II) C major (III) D major number of octave frequency Output fre- Tone Output fre- Tone Output fre- Tone divider quency Hz signal quency Hz signal quency Hz signal ____________________________________________________________ ______________ 1 20' - 1 8372.02 C 8869.84 C♯ 9397.21 D 2 20' - 1 7902.13 B 8372.02 C 8869.84 C♯ 3 20' - 3 7458.62 A♯ 7902.13 B 8372.02 C 4 20' - 4 7040.00 A 7458.62 A♯ 7902.13 B 5 20' - 5 6644.88 C♯ 7040.00 A 7458.62 A♯ 6 20' - 6 6271.93 G 6644.88 G♯ 7040.00 A 7 20' - 7 5919.91 F♯ 6271.93 G 6644.88 G♯ 8 20' - 8 5587.65 F 5919.91 F♯ 6271.93 G 9 20' - 9 5274.04 E 5587.65 F 5919.91 F♯ 10 20' - 10 4978.03 D♯ 5274.04 E 5587.65 F 11 20' - 11 4698.64 D 4978.03 D♯ 5274.04 E 12 20' - 12 4434.94 C♯ 4698.64 D 4978.03 D♯ Input frequency 2.00024 MHz 2.11741 MHz 2.24079 MHz Contact number of 60 - 0 60 - 2 60 - 3 change-over switch ____________________________________________________________ ______________
The above is the case where transposition is to the higher side. As shown in FIG. 6, the high frequency oscillator 10' is provided on its output side with a frequency divider 70 comprising a plurality of counter circuits, so that the oscillation frequencies thereof are lowered by steps at each counter circuit. If the output terminals thereof are selectively connected to the OR circuit 30 and the NOT circuit 40 through a change-over switch 80, a transposition to the lower side can be easily effected by selective connection of the change-over switch 80 and selective connection of the change-over switch 60. Additionally, movement of an octave becomes possible by that the frequency dividing ratio of each counter circuit of the frequency divider 70 is designed to be 1/2. If, under this condition, the oscillation frequency of the high frequency oscillator 10 is made higher by several octaves, movement of an octave either to the higher side or the lower side becomes possible by selective connection of the change-over switch 80. Accordingly, a player can play any octave at a predetermined position, without especially moving his position.
FIG. 7 shows the case where the NOT circuit in FIGS. 4 and 6 is omitted. In this case, the oscillation frequency of the high frequency oscillator 10' is doubled to be 4.00048 MHz and this frequency is made to be 1/2 through a binary circuit 90. At the same time, positive and negative wave forms as shown in FIGS. 5 (a) and (c) are taken from the binary circuit 90. Thus, this only slightly different from the case of FIGS. 4 and 6.
The above explanation has been given with reference to the second frequency dividing system of an octave frequency divider, but this is similar also in the case of the first system except only that the oscillation frequencies of the high frequency oscillator 10 and the transposition oscillator become smaller.
Thus, according to this invention, the oscillation frequency of the high frequency oscillator is properly added to any of the oscillation frequencies of the transposition oscillator comprising the plurality of counter circuits so as to produce an input for the octave frequency divider so that, by means of selecting the adding frequency, and desired transposition can be effected. Accordingly, the playing of any desired music with sharps or flats can be effected by a player as long as he can play in C major.