Title:
ELECTRONIC MUSICAL INSTRUMENT CAPABLE OF TRANSPOSING
United States Patent 3824325
Abstract:
A transposing electronic musical instrument wherein 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 counter circuits to obtain octave tone signals. A frequency divider for transposition comprising counter circuits is interposed between the high frequency oscillator and the octave frequency divider such that the output terminals of these counter circuits can be selectively connected to the octave frequency divider.
US Patent References:
Transposition apparatus for electrical musical instrument
Bode - March 1962 - 3023659
Electric organ transposing switch
Wick - April 1962 - 3030848
APPARATUS FOR TUNING MUSICAL INSTRUMENTS
Gossel - April 1970 - 3509454
DIGITAL ELECTRONIC KEYBOARD INSTRUMENT WITH AUTOMATIC TRANSPOSITION
Deutsch - October 1971 - 3610800
KEYBOARD TRANSPOSITION OF ELECTRICAL MUSICAL INSTRUMENTS
Derry - July 1972 - 3674907
Transposition apparatus for electrical musical instrument
Bode - March 1962 - 3023659
Electric organ transposing switch
Wick - April 1962 - 3030848
APPARATUS FOR TUNING MUSICAL INSTRUMENTS
Gossel - April 1970 - 3509454
DIGITAL ELECTRONIC KEYBOARD INSTRUMENT WITH AUTOMATIC TRANSPOSITION
Deutsch - October 1971 - 3610800
KEYBOARD TRANSPOSITION OF ELECTRICAL MUSICAL INSTRUMENTS
Derry - July 1972 - 3674907
Inventors:
Obayashi, Nobuharu (Hamana-gun, JA)
Sakashita, Tetsuzi (Hamamatsu, JA)
Sakashita, Tetsuzi (Hamamatsu, JA)
Application Number:
05/352628
Publication Date:
07/16/1974
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, 984/338, 84/685, 84/678
International Classes:
G10H1/20; G10H1/02
Field of Search:
84/1.01,1.17,445,446,447,448
Primary Examiner:
Wilkinson, Richard B.
Assistant Examiner:
Witkowski, Stanley J.
Attorney, Agent or Firm:
Waters, Eric H.
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 generating twelve tone signals based on a twelve tempered scale, a transposition frequency divider including counter circuits, and means coupling said octave frequency divider to the output side of said oscillator via said transposition frequency divider such that the latter said counter circuits can be selectively connected to the octave frequency divider.
2. An instrument as claimed in claim 1 wherein said means includes a multiple position selector switch coupling the latter said counter circuits to said octave frequency divider.
3. An instrument as claimed in claim 2 comprising octave change-over means connected between said oscillator and transposition frequency divider and including a plurality of counter circuits and a selector switch connecting said counter circuits to said transposition frequency 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 generating twelve tone signals based on a twelve tempered scale, a transposition frequency divider including counter circuits, and means coupling said octave frequency divider to the output side of said oscillator via said transposition frequency divider such that the latter said counter circuits can be selectively connected to the octave frequency divider.
2. An instrument as claimed in claim 1 wherein said means includes a multiple position selector switch coupling the latter said counter circuits to said octave frequency divider.
3. An instrument as claimed in claim 2 comprising octave change-over means connected between said oscillator and transposition frequency divider and including a plurality of counter circuits and a selector switch connecting said counter circuits to said transposition frequency divider.
Description:
FIELD OF INVENTION
This invention relates to a transposing type electronic musical instrument.
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. In the case of C major, for example, C, D, E, F, F, A, B, C, are played by using natural keys. D major however beings with the D tone and natural keys and chromatic keys must be used. Thus, the operation of chromatic keys is required due to the transposition and this requirement applies to the case of an electronic musical instrument. Thus, playing with transposition is very difficult for a beginner.
SUMMARY OF INVENTION
This invention relates to an electronic musical instrument wherein flat families and sharp families can be played with the use of the natural keys only, in almost the same manner as in the case of C major by shifting the tone source frequencies corresponding and relating to respective keys.
An object of the invention is to provide an electronic musical instrument such that any desired music can be freely played through selection of a switch by a beginner who can play in C major.
A musical instrument of the invention is characterized by being of the type wherein a main 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 counter circuits to obtain a plurality of octave tone signals. A frequency divider for transposition is employed comprising counter circuits interposed between the high frequency oscillator and the octave frequency divider so that output terminals of these counter circuits can be selectively connected to 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 respective blocks diagrams showing a frequency dividing system of an octave frequency divider;
FIGS. 4 and 5 are respective block diagrams showing an example of this invention; and
FIG. 6 is a block diagram showing another embodiment of this invention.
DETAILED DESCRIPTION
As is shown in FIG. 1 in the case of C major, for example, C, D, E, F, G, A, B, C, are played by using natural keys K1, K3, K5, K6, K8, K10 and K12. In the case of D major, however, this begins with the D tone and accordingly natural keys K3, K5, chromatic key K7, natural keys K8, K10, K12 and K13, chromatic key K14 and natural key K15 must be used. Thus, the operation of chromatic keys are required, due to the transposition and this requirement applies to the case of all electronic musical instruments. Therefore, playing with transposition is very difficult for the beginner.
As for a system involving an octave frequency divider, there are two systems. FIG. 2 shows one system with octave frequency divider 20 (as, for example, employed in D. Gossel U.S. Pat. 3,509,454), and the same comprises that twelve counter circuits (20-1) . . . . (20-12) are connected in series with one another. The frequency dividing ratio of each is 196/185. If it is desired that a frequency of 8372.02 Hz be oscillated from the first counter circuit (20-11), the oscillation frequency f m of a high frequency oscillator 10 connected to the input terminal of the octave frequency divider 20 must be 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 musical tone signals thereof are indicated in parentheses. Though not illustrated, these oscillation frequencies are each further frequency-divided by respective pluralities of counter circuits, for example, into seven stages when it is intended, for example, to cover seven octaves of the whole scale of a piano.
FIG. 3 shows the other system employing an octave frequency divider 20'. This system comprises twelve counter circuits (20'-1) . . . . . (20'-12) connected in parallel with one another to a single common high frequency oscillator 10'. The frequency dividing ratios thereof are 1/239, 1/253 . . . . . 1/451 as shown in this figure. Accordingly, if it is desired that 8360.21 Hz be generated from the first counter circuit (20'-1), the oscillation frequency f m ' 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 almost equal to those in the case shown in FIG. 2.
This invention is characterized in that a frequency divider for transposition 30 or 30' is provided as shown in FIGS. 4 or 5 preceding the octave frequency divider 20 or 20', and output terminals of a plurality of counter circuits constituting the transposition frequency divider 30 or 30' are selectively connected to the octave frequency divider 20 or 20' positioned at the succeeding stage thereof.
The transposition frequency divider 30 shown in FIG. 4 has the same frequency dividing ratio as that of the octave frequency divider 20 shown in FIG. 2. Output terminals (30-1a) . . . . . (30-12a) of counter circuits (30-1) . . . . . (30-12) constituting the transposition frequency divider 30 are connected to respective stationary contacts (40-1) . . . . . (40-12) of a changeover switch 40, and a movable contact 40a thereof is connected to the octave frequency divider 20. Thus, if the octave frequency divider 20 requires, for example, 8869.84 Hz as shown in FIG. 2 as its highest input frequency, the oscillation frequency of the high frequency oscillator 10 becomes 1 divided by the frequency dividing ratio thereof, that is, 9397.28 Hz obtained by multiplying the frequency by 196/185. Accordingly, the frequencies obtained at the output terminals (30-1a) . . . . . (30-12a) of the counter circuits (30-1) . . . . . (30-12) constituting the transposition frequency divider 30 become those shown in Table 1 below. The musical tone signals of these frequencies are as shown in the right hand column thereof.
TABLE 1 ______________________________________ Contact No. Frequency Tone signal (major) ______________________________________ 1 40-1 8869.84 C 2 40-2 8372.02 B 3 40-3 7902.13 A♯ (B♭) 4 40-4 7458.62 A 5 40-5 7040.00 G♯ (A♭) 6 40-6 6644.88 G 7 40-7 6271.93 F♯ (G♭) 8 40-8 5919.91 F 9 40-9 5587.65 E 10 40-10 5274.04 D♯ (E♭) 11 40-11 4978.03 D 12 40-12 4698.64 C♯ (D♭) ______________________________________
If the movable contact 40a of the change-over switch 50 is connected to the stationary contact (40-1) as shown in FIG. 4, the octave frequency divider 20 is supplied with 8869.84 Hz and the frequencies as described in column (1) of Table 2 below can be obtained at the output terminals (20-1a) . . . . . (20-12a). This is the same as the case of the octave frequency divider 20 shown in FIG. 2. Under this condition, C major can be played by using natural keys as in conventional electronic musical instruments. If, then, the movable contact (40a) is connected to the stationary contact (40-2), the octave frequency divider 20 is supplied with the frequency of 8372.02, that is, the frequency of a B signal, and the oscillation frequencies transposed by one interval as shown in column (II) of Table 2 can be obtained at the output terminals (20-1a) . . . . . (20-12a). Namely, the tones generated when natural keys are operated are those of the condition that the same have been transposed by one interval. Thus, the playing of B major becomes possible by playing in almost the same manner as in C major using natural keys only, without using any chromatic keys.
If, then, the movable contact (40a) is connected to the stationary contact (40-3), it is transposed further by one interval as shown in column (III) of same Table. Accordingly, the playing of A major becomes possible only by using natural keys only. Thus, the playing of various tones can be simply effected only with natural keys, without using chromatic keys, by properly selecting the stationary contacts (40-1) . . . . . (40-12) by a turning of the movable contact (40a).
TABLE 2 ______________________________________ (I) C major (II) B major (III) A major Counter circuit number of octave frequency divider Output frequency Hz Tone signal Output frequency Hz Tone signal Output frequency Hz Tone signal ______________________________________ 20-1 8372.02 C 7902.13 B 7458.62 A♯ 20-2 7902.13 B 7458.62 A♯ 7040.00 A 20-3 7458.62 A♯ 7040.00 A 6644.88 G♯ 20-4 7040.00 A 6644.88 G♯ 6271.93 G 20-5 6644.88 G♯ 6271.93 G 5919.91 F♯ 20-6 6271.93 G 5919,91 F♯ 5587.65 F 20-7 5919.91 F♯ 5587.65 F 5274.04 E 20-8 5587.65 F 5274.04 E 4978.03 D♯ 20-9 5274.04 E 4978.03 D♯ 4698.64 D 20-10 4978.03 D♯ 4698.64 D 4434.94 C♯ 20-11 4698.64 D 4434.94 C♯ 4186.04 C 20-12 4434.94 C♯ 4186.04 C 3951.10 B Input frequency Hz 8869.84 8372.02 7902.12 Change-over switch contact number 40-1 40-2 40-3 ______________________________________
FIG. 5 shows a case where, between the octave frequency divider 20' and the high frequency oscillator 10' as shown in FIG. 3, a transposing frequency divider 30' of the same frequency dividing system as the octave frequency divider 20' is interposed. If it is assumed that the highest frequency which the octave frequency divider 20' requires is 2.00024 MHz, what is required is only that a frequency of 478 MHz, which is obtained by a technique in which the foregoing frequency is multiplied by 1 divided by the frequency dividing ratio of the first stage of the transposition frequent divider 30', be generated by the high-frequency oscillator 10'. By properly selecting the stationary contact (40'-1) . . . . (40'-12) by a movable contact (40a') of a change-over switch 40', transposition selection can be made in the same manner as in the case of FIG. 4 and the playing of any desired key can be performed freely with natural keys only.
The above has been explained relative to the case where there is provided at the preceding stage of the octave frequency divider 20,20' a transposing frequency divider 30, 30' having the same frequency dividing ratio, but the same result can be obtained where the frequency divider of the other frequency dividing system is provided. When, in FIG. 4 for example, the transposing frequency divider 30 is replaced by 30' if it is assumed that the highest input frequency required by the octave frequency divider 20 is 8869.84 Hz, what is different is only that the high frequency oscillator of 1 MHz is required.
FIG. 6 shows a case where an octave change-over device 50 is interposed between the high frequency oscillator 10 and the transposing frequency divider 30, and the octave change-over device 50 comprises a plurality of counter circuits. It is so arranged that output terminals (50-1) . . . . . (50-5) thereof are selectively connected to the transposition frequency divider 30, for example, through a rotary switch 60.
The frequency dividing ratio is one-half and if it is assumed that 9397.27 Hz is generated from the center output terminal (50-3) in the same manner as in the case of FIG. 4, the oscillation frequency of the high frequency oscillator 10 becomes 37,589.08 Hz. Thus, by means of a change-over connection of the rotary switch 60, the octave which is to be the main portion of the playing can be always placed at the front position of a player and playing is thus facilitated. This is applicable in almost the same manner to the example of FIG. 5.
Thus, according to this invention, by properly selecting the connection between the output terminals of the counter circuits constituting the transposing frequency divider and the octave frequency divider, tones corresponding to respective keys can be transposed, so that a playing of any tone can be effected with the use of natural keys only and the playing of any tone can be readily accomplished even by a beginner if he can play in C major.
In the above, for example, in FIG. 2, the output signal of each terminal is frequency-divided by 2 or multiples thereof to provide, for example, seven octaves of a note in harmonic relationship. Thus, the frequency dividers 20 and 20' are octave frequency dividers, while the frequency dividers 30 and 30' are for transposition.
This invention relates to a transposing type electronic musical instrument.
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. In the case of C major, for example, C, D, E, F, F, A, B, C, are played by using natural keys. D major however beings with the D tone and natural keys and chromatic keys must be used. Thus, the operation of chromatic keys is required due to the transposition and this requirement applies to the case of an electronic musical instrument. Thus, playing with transposition is very difficult for a beginner.
SUMMARY OF INVENTION
This invention relates to an electronic musical instrument wherein flat families and sharp families can be played with the use of the natural keys only, in almost the same manner as in the case of C major by shifting the tone source frequencies corresponding and relating to respective keys.
An object of the invention is to provide an electronic musical instrument such that any desired music can be freely played through selection of a switch by a beginner who can play in C major.
A musical instrument of the invention is characterized by being of the type wherein a main 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 counter circuits to obtain a plurality of octave tone signals. A frequency divider for transposition is employed comprising counter circuits interposed between the high frequency oscillator and the octave frequency divider so that output terminals of these counter circuits can be selectively connected to 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 respective blocks diagrams showing a frequency dividing system of an octave frequency divider;
FIGS. 4 and 5 are respective block diagrams showing an example of this invention; and
FIG. 6 is a block diagram showing another embodiment of this invention.
DETAILED DESCRIPTION
As is shown in FIG. 1 in the case of C major, for example, C, D, E, F, G, A, B, C, are played by using natural keys K1, K3, K5, K6, K8, K10 and K12. In the case of D major, however, this begins with the D tone and accordingly natural keys K3, K5, chromatic key K7, natural keys K8, K10, K12 and K13, chromatic key K14 and natural key K15 must be used. Thus, the operation of chromatic keys are required, due to the transposition and this requirement applies to the case of all electronic musical instruments. Therefore, playing with transposition is very difficult for the beginner.
As for a system involving an octave frequency divider, there are two systems. FIG. 2 shows one system with octave frequency divider 20 (as, for example, employed in D. Gossel U.S. Pat. 3,509,454), and the same comprises that twelve counter circuits (20-1) . . . . (20-12) are connected in series with one another. The frequency dividing ratio of each is 196/185. If it is desired that a frequency of 8372.02 Hz be oscillated from the first counter circuit (20-11), the oscillation frequency f m of a high frequency oscillator 10 connected to the input terminal of the octave frequency divider 20 must be 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 musical tone signals thereof are indicated in parentheses. Though not illustrated, these oscillation frequencies are each further frequency-divided by respective pluralities of counter circuits, for example, into seven stages when it is intended, for example, to cover seven octaves of the whole scale of a piano.
FIG. 3 shows the other system employing an octave frequency divider 20'. This system comprises twelve counter circuits (20'-1) . . . . . (20'-12) connected in parallel with one another to a single common high frequency oscillator 10'. The frequency dividing ratios thereof are 1/239, 1/253 . . . . . 1/451 as shown in this figure. Accordingly, if it is desired that 8360.21 Hz be generated from the first counter circuit (20'-1), the oscillation frequency f m ' 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 almost equal to those in the case shown in FIG. 2.
This invention is characterized in that a frequency divider for transposition 30 or 30' is provided as shown in FIGS. 4 or 5 preceding the octave frequency divider 20 or 20', and output terminals of a plurality of counter circuits constituting the transposition frequency divider 30 or 30' are selectively connected to the octave frequency divider 20 or 20' positioned at the succeeding stage thereof.
The transposition frequency divider 30 shown in FIG. 4 has the same frequency dividing ratio as that of the octave frequency divider 20 shown in FIG. 2. Output terminals (30-1a) . . . . . (30-12a) of counter circuits (30-1) . . . . . (30-12) constituting the transposition frequency divider 30 are connected to respective stationary contacts (40-1) . . . . . (40-12) of a changeover switch 40, and a movable contact 40a thereof is connected to the octave frequency divider 20. Thus, if the octave frequency divider 20 requires, for example, 8869.84 Hz as shown in FIG. 2 as its highest input frequency, the oscillation frequency of the high frequency oscillator 10 becomes 1 divided by the frequency dividing ratio thereof, that is, 9397.28 Hz obtained by multiplying the frequency by 196/185. Accordingly, the frequencies obtained at the output terminals (30-1a) . . . . . (30-12a) of the counter circuits (30-1) . . . . . (30-12) constituting the transposition frequency divider 30 become those shown in Table 1 below. The musical tone signals of these frequencies are as shown in the right hand column thereof.
TABLE 1 ______________________________________ Contact No. Frequency Tone signal (major) ______________________________________ 1 40-1 8869.84 C 2 40-2 8372.02 B 3 40-3 7902.13 A♯ (B♭) 4 40-4 7458.62 A 5 40-5 7040.00 G♯ (A♭) 6 40-6 6644.88 G 7 40-7 6271.93 F♯ (G♭) 8 40-8 5919.91 F 9 40-9 5587.65 E 10 40-10 5274.04 D♯ (E♭) 11 40-11 4978.03 D 12 40-12 4698.64 C♯ (D♭) ______________________________________
If the movable contact 40a of the change-over switch 50 is connected to the stationary contact (40-1) as shown in FIG. 4, the octave frequency divider 20 is supplied with 8869.84 Hz and the frequencies as described in column (1) of Table 2 below can be obtained at the output terminals (20-1a) . . . . . (20-12a). This is the same as the case of the octave frequency divider 20 shown in FIG. 2. Under this condition, C major can be played by using natural keys as in conventional electronic musical instruments. If, then, the movable contact (40a) is connected to the stationary contact (40-2), the octave frequency divider 20 is supplied with the frequency of 8372.02, that is, the frequency of a B signal, and the oscillation frequencies transposed by one interval as shown in column (II) of Table 2 can be obtained at the output terminals (20-1a) . . . . . (20-12a). Namely, the tones generated when natural keys are operated are those of the condition that the same have been transposed by one interval. Thus, the playing of B major becomes possible by playing in almost the same manner as in C major using natural keys only, without using any chromatic keys.
If, then, the movable contact (40a) is connected to the stationary contact (40-3), it is transposed further by one interval as shown in column (III) of same Table. Accordingly, the playing of A major becomes possible only by using natural keys only. Thus, the playing of various tones can be simply effected only with natural keys, without using chromatic keys, by properly selecting the stationary contacts (40-1) . . . . . (40-12) by a turning of the movable contact (40a).
TABLE 2 ______________________________________ (I) C major (II) B major (III) A major Counter circuit number of octave frequency divider Output frequency Hz Tone signal Output frequency Hz Tone signal Output frequency Hz Tone signal ______________________________________ 20-1 8372.02 C 7902.13 B 7458.62 A♯ 20-2 7902.13 B 7458.62 A♯ 7040.00 A 20-3 7458.62 A♯ 7040.00 A 6644.88 G♯ 20-4 7040.00 A 6644.88 G♯ 6271.93 G 20-5 6644.88 G♯ 6271.93 G 5919.91 F♯ 20-6 6271.93 G 5919,91 F♯ 5587.65 F 20-7 5919.91 F♯ 5587.65 F 5274.04 E 20-8 5587.65 F 5274.04 E 4978.03 D♯ 20-9 5274.04 E 4978.03 D♯ 4698.64 D 20-10 4978.03 D♯ 4698.64 D 4434.94 C♯ 20-11 4698.64 D 4434.94 C♯ 4186.04 C 20-12 4434.94 C♯ 4186.04 C 3951.10 B Input frequency Hz 8869.84 8372.02 7902.12 Change-over switch contact number 40-1 40-2 40-3 ______________________________________
FIG. 5 shows a case where, between the octave frequency divider 20' and the high frequency oscillator 10' as shown in FIG. 3, a transposing frequency divider 30' of the same frequency dividing system as the octave frequency divider 20' is interposed. If it is assumed that the highest frequency which the octave frequency divider 20' requires is 2.00024 MHz, what is required is only that a frequency of 478 MHz, which is obtained by a technique in which the foregoing frequency is multiplied by 1 divided by the frequency dividing ratio of the first stage of the transposition frequent divider 30', be generated by the high-frequency oscillator 10'. By properly selecting the stationary contact (40'-1) . . . . (40'-12) by a movable contact (40a') of a change-over switch 40', transposition selection can be made in the same manner as in the case of FIG. 4 and the playing of any desired key can be performed freely with natural keys only.
The above has been explained relative to the case where there is provided at the preceding stage of the octave frequency divider 20,20' a transposing frequency divider 30, 30' having the same frequency dividing ratio, but the same result can be obtained where the frequency divider of the other frequency dividing system is provided. When, in FIG. 4 for example, the transposing frequency divider 30 is replaced by 30' if it is assumed that the highest input frequency required by the octave frequency divider 20 is 8869.84 Hz, what is different is only that the high frequency oscillator of 1 MHz is required.
FIG. 6 shows a case where an octave change-over device 50 is interposed between the high frequency oscillator 10 and the transposing frequency divider 30, and the octave change-over device 50 comprises a plurality of counter circuits. It is so arranged that output terminals (50-1) . . . . . (50-5) thereof are selectively connected to the transposition frequency divider 30, for example, through a rotary switch 60.
The frequency dividing ratio is one-half and if it is assumed that 9397.27 Hz is generated from the center output terminal (50-3) in the same manner as in the case of FIG. 4, the oscillation frequency of the high frequency oscillator 10 becomes 37,589.08 Hz. Thus, by means of a change-over connection of the rotary switch 60, the octave which is to be the main portion of the playing can be always placed at the front position of a player and playing is thus facilitated. This is applicable in almost the same manner to the example of FIG. 5.
Thus, according to this invention, by properly selecting the connection between the output terminals of the counter circuits constituting the transposing frequency divider and the octave frequency divider, tones corresponding to respective keys can be transposed, so that a playing of any tone can be effected with the use of natural keys only and the playing of any tone can be readily accomplished even by a beginner if he can play in C major.
In the above, for example, in FIG. 2, the output signal of each terminal is frequency-divided by 2 or multiples thereof to provide, for example, seven octaves of a note in harmonic relationship. Thus, the frequency dividers 20 and 20' are octave frequency dividers, while the frequency dividers 30 and 30' are for transposition.