Description:
This invention relates to an automatic rhythm playing apparatus and, U. S. particularly, to an automatic rhythm playing apparatus which is capable of automatically changing a rhythm during performance of the apparatus and also is capable of producing various types of special rhythm patterns besides standard rhythm patterns.
The applicant of the present invention proposed in the copending U.S. patent application Ser. No. 239,178 filed Mar. 29, 1972 entitled "An Automatic Rhythm Playing Apparatus" an automatic rhythm playing apparatus which comprises memory means storing information corresponding to note arrangements of a plurality or rhythms for each of percussion instruments, first address means for providing circulating address signals to the memory means, second address means for providing stationary address signals corresponding to a selected rhythm to be sounded to the memory means, said memory means producing output signals having the note arrangement of the selected rhythm in response to the circulating and stationary address signals, and means for producing percussion instrument sound signals by application thereto of the output signals of the memory means thereby to obtain a rhythm sound signal consisting of a plurality of percussion instrument sound signals.
The proposed automatic rhythm playing apparatus sufficiently performs its function if a single rhythm is to be played continuously throughout the whole performance of a music number. The proposed apparatus, however, is incapable of automatically changing the rhythm during performance of the apparatus. It is also incapable of producing special rhythms which are different from the standard rhythms stored in the memory and therefore may be considered anomalous compared with the standard rhythms.
It is, therefore, an object of the invention to provide an automatic rhythm playing apparatus which is capable of automatically changing the rhythm in accordance with a preset order without any particular manipulation during the performance of the apparatus. According to the invention, tediousness or monotonousness which tends to accompany the playing of one single rhythm throughout the whole performance of a musical number is eliminated and the effect of the performance can be enhanced to a large extent.
It is another object of the invention to provide an automatic rhythm playing apparatus which is capable of selectively producing various rhythm patterns of anomalous types besides standard rhythm patterns. This feature of the invention affords variety to the rhythm pattern and thereby gives, so to speak, a human touch to the performance of the rhythm by the apparatus.
These and other objects and features of the invention will become more apparent from the description made hereinbelow with reference to the accompanying drawings in which:
FIG. 1 is a block diagram showing one preferred embodiment of the automatic rhythm playing apparatus according to the invention;
FIG. 2 is a block diagram showing another embodiment of the automatic rhythm playing apparatus according to the invention; and
FIG. 3a to 3c are respectively waveform charts. FIGS. 3a and 3b illustrate examples of waveforms appearing in the parts of the apparatus shown in FIG. 2 when it plays a selected rhythm (e.g. bossanova), and FIG. 3c illustrates examples of waveforms appearing in the parts of the apparatus shown in FIG. 2 when it plays a selected special rhythm which is a variation of bossanova.
Referring to FIG. 1, a clock pulse oscillator 1 has tempo adjusting means for changing the oscillating frequency of clock pulses. The clock pulses CP from the oscillator 1 are applied to a dynamic counter 2. The dynamic counter 2 may, for example, be of a four-staged one comprising flip-flops connected in series in four stages. The counter 2 successively receives the clock pulses CP and repeats its counting operation, being reset at every 16th pulse. Accordingly, there are 16 states of outputs A1 to A4 of the ounter 2, i.e. from 0000 up to 1111. The outputs A1 to A4 are fed to a decoder 3. The decoder 3 provides outputs only to an output line which corresponds to either one of the aforementioned 16 states. This output of the decoder 3 is applied to a memory 4 as an address signal.
A rhythm selection circuit 6 is provided for obtaining an address signal proper to each of various rhythms. The rhythm selection circuit 6 has 16 rhythm selection switches S1 to S16 respectively corresponding to one of the rhythms of, for example, march, tango, cha-cha-cha, swing, waltz, slow rock, jazz rock, bossanova, rumba, beguine, ballad, rock 2, rock 3, bossanova II, mambo and samba (Reference should be made to the aforementioned co-pending application). The rhythm selection circuit 6 is further provided with gates G1 to G16 which are respectively connected in parallel with these rhythm selection switches S1 to S16. Either one of states of outputs A5 to A8 as shown in Table I which is peculiar to a selected rhythm is obtained by closing one of the switches which corresponds to the selected rhythm or by causing, as will be described later, a desired gate among the gates G1 to G16 to be selectively opened upon application thereto of a rhythm designating signal from an automatic rhythm changing circuit 9. --------------------------------------------------------------------------- Table I
SW Rhythm A5 A6 A7 A8 __________________________________________________________________________ S1 march 1 1 1 1 S2 tango 0 1 1 1 S3 cha-cha-cha 1 0 1 1 S4 swing 0 0 1 1 S5 waltz 1 1 0 1 S6 slow rock 0 1 0 1 S7 jazz rock 1 0 0 1 S8 bossanova I 0 0 0 1 S9 rumba 1 1 1 0 S10 beguine 0 1 1 0 S11 ballad 1 0 1 0 S12 rock 2 0 0 1 0 S13 rock 3 1 1 0 0 S14 bossanova II 0 1 0 0 S15 mambo 1 0 0 0 S16 samba 0 0 0 __________________________________________________________________________
In the Table I rhythms corresponding to the states of address signals A5 to A8 are shown as examples. There are 16 states of the outputs A5 to A8, i. e. from 0000 to 1111 either one of which is fed to a decoder 5. The state thus fed to the decoder 5 remains unchanged until the selected rhythm is changed. The decoder 5 provides an output only to an output line corresponding to the aforementioned state. This output of the decoder 5 is also applied to the memory 4 as an address signal. Decoders 3 and 5 are of the type capable of converting four binary inputs into sixteen digital outputs and are well known, as referred to for example in U.S. Pat. No. 3,610,801 to Fredkin et al (decoding matrix 19).
The memory 4 consists, for example, of a read only memory. Read only memories of this type are well known as disclosed for example in U.S. Pat. No. 3,529,299 to Chung and require only routine effort of a person skilled in the art to utilize the memory for performing the desired functions in accordance with the present invention. At addresses in the memory 4 to be accessed by the address signals from the decoders 3 and 5, information is stored in accordance with the note arrangement of each rhythm. The information is successively read out by the address signals A1 to A4 and A5 to A8 thereby producing successive outputs for each percussion instrument sound. Since at this time the state of the address signals A1 to A4 is repeated at every 16th pulse of the clock pulses CP, the state of outputs of the memory 4 is also repeated. Thus, measures of each rhythm are repeatedly obtained.
The outputs of the memory 4 are applied to a percussion instrument sound signal generating circuit 8 via a gate circuit 7. The gate circuit 7 includes, though not shown in FIG. 1, gate elements respectively corresponding to the outputs of the memory 4 and a waveshaping circuit which receives the pattern pulses and produces control signals of a sharp waveform. The outputs B1 to B8 of the memory 4 respectively correspond to maracas, claves, cymbals, snare drum, high conga, low conga, bongo and bass drum. When the output is "1", a percussion instrument sound signal corresponding to this output is produced from the percussion instrument sound signal generating circuit 8. The percussion instrument sound signal generating circuit 8 has eight sound source circuits which respectively produce sound signals of maracas, claves, cymbals, snare drum, high conga, low conga, bongo and bass drum in response to the output signal of the memory 4. A rhythm sound signal which is composed of the percussion instrument sound signals produced in the circuit 8 is led to a common output line W.
An automatic rhythm changing circuit 9 comprises a ring counter 10, a memory 11 and a preset switch matrix circuit 12. The ring counter 10 includes a shift register SR having stages SR1 to SRn and a stage selection switch SEL which is provided for selecting a stage of the shift register to be used. The overflow outputs of the dynamic counter 2 are applied through a switch S to each stage of the shift register SR as shift pulses. The first stage of the shift register SR has previously been provided by some suitable means with a signal 1 which is stored there. Accordingly, each time the overflow output of the dynamic counter 2 is applied to the shift register SR, the signal 1 is shifted from the stage SR1 to SR2, SR3 . . . SRn. The output of each stage SR1 to SRn of the shift register SR is connected to the input of the memory 11. The stage selection switch SEL has terminals t1 to tn connected respectively to the output of each stage SR1 to SRn and a movable contact H connected to the input of the first stage SR1. The movable contact H is connected to a selected one of the terminals t1 to tn, so that the signal 1 from the shift register stage connected to the selected terminal is fed back to the input of the stage SR1. Accordingly, if, for example, the contact H is connected to the terminal t2, the shift register stage SR3 and the subsequent stages are not used.
Since the overflow pulse from the dynamic counter 2 is produced for every one measure or two measures, a required number of the stages of the shift register SR for a piece of music consisting, for example, of 100 measures is 100 or 50. (For convenience of explanation, it is now assumed that the overflow pulse from the counter 2 is produced for every one measure in FIG. 1.)
The output pulse 1 of any one stage of the shift register SR during its shifting operation is applied to the input of the next stage and also to the memory 11 in which the signal is stored. The time during which the signal is stored in the memory 11 corresponds to the time of one measure.
The memory 11 has a plurality of output lines l1 to ln. Lines K1 to K16 respectively connected to the control terminals of the gates G1 to G16 are provided across the output lines l1 to ln. Preset switches PS1-1 to PS1-n, . . . PS16-1 to PS16-n are respectively connected to the lines l1 to ln at one end and the lines K1 to K16 at the other end at places where the lines l1 to ln cross the lines K1 to Kn, thereby constituting a preset switch matrix circuit 12.
When the preset switch PS is closed, the output of the memory 11 is applied as a rhythm designating signal to the corresponding gate among the gates G1 to G16 so as to open the gate. Thus, as in the case wherein the rhythm selection switch connected in parallel with the gate is closed, either one of the states of the stationary address signals A5 to A8 is produced.
Assume now that a music number is played in such a manner that the mood of the music is changed during performance by changing its rhythm. If, for example, the first to eight measures are to be played in the rhythm of tango and the ninth to eighteenth measures in the rhythm of cha cha cha, the preset switches PS2-1 to PS2-8 and PS6-9 to PS6-18 are closed, while all other preset switches remain open. The contact H of the stage selection switch SEL is switched to the terminal t18.
When the overflow pulse of the dynamic counter 2 is applied to the shift register SR, the signal 1 in the stage SR 1 is shifted to the stage SR2. At this time, the signal 1 is stored in the memory 11 which, in turn, provides an output to the line l1. This output is applied to the gate G2 via the preset switch PS2-1 and causes the gate G2 to be opened. Accordingly, the stage of the address signals A5 to A8 from the rhythm selection circuit 6 becomes 0111. After one measure the signal 1 is shifted from the stage SR2 to the stage SR3 and simultaneously is applied to the memory 11. Then the memory 11 provides an output to the line l2. This output is applied to the gate G2 via the present switch PS2-2. The address signals A5 to A8 remain 0111. The performance continues in this manner until the eighth measure ends. When the signal 1 is shifted from the stage SR9 to the stage SR10 to start the ninth measure, the output of the stage SR9 is supplied to the memory 11, thereby producing an output on the line l9. This output is applied to the gate G6 via the preset switch PS6-9. Accordingly, the state of the address signals A5 to A8 of the rhythm selection circuit 6 becomes 1011, whereby the rhythm of cha-cha-cha is now selected. Subsequently, outputs are successively produced on the lines l10, l11 . . . l18 as measures advance. Since the gate G6 remains open, the apparatus continues to play the rhythm of cha-cha-cha. When the signal 1 is shifted from the stage SR18, the signal 1 is shifted to the stage SR1 via the stage selection switch SEL. Accordingly, the next shift pulse causes the signal 1 to be shifted from the stage SR1 to the stage SR2, thereby changing the rhythm to tango. Memory 11 is also a read only memory of a type well known and may be for example of the type shown in U.S. Pat. No. 3,156,829 to Richards which would require only routine effort on the part of a person skilled in the art to utilize for the purposes of the present invention.
In the above described example, the rhythm of the music is changed from the first rhythm to the second rhythm and this change is repeated thereafter during performance of the music. It is of course possible to preset, by selectively closing the preset switches, a plurality of selected rhythms in a desired order over the whole piece of music and automatically switch the rhythm from one to another during the performance of the music.
According to the foregoing embodiment, the player is relieved from the troublesome operation for changing a rhythm during performance of a music by presetting a plurality of rhythms to be played by means of the preset switches. This greatly simplifies the performance of electronic musical instruments. Further, if switching of rhythms in one piece of music is made in such a manner that a plurality of rhythms of the same time are switched one from another, it will add variety to the mood of the music and improve the effect of the performance.
In case the automatic changing of the rhythm is not required, the switch S is opened and a desired rhythm is selected by closing either one of the rhythm selection switches S1 to S16.
Referring now to FIG. 2, another embodiment of the automatic rhythm playing apparatus according to the invention will be described. This embodiment is adapted for producing rhythms having an anomalous rhythm pattern compared with a standard rhythm pattern. The construction for obtaining predetermined standard rhythm sound signals are substantially the same as in the previously described embodiment and description thereof will be omitted.
A rhythm pattern changing circuit 16 is provided between a clock pulse oscillator 1 and a gate circuit 7. The rhythm pattern changing circuit 16 comprises a clock frequency dividing circuit 13 having one or more flip-flop stages, for example, F1, F2 . . . , a rhythm pattern change switch 14 and a waveshaping circuit 15.
The switch 14 has a plurality of fixed contacts K0, K1, K2 . . . and a movable contact J. The circuit 16 is constructed so that a signal CP from the clock pulse oscillator 1 is supplied to the contact K0 and also to the first frequency dividing stage F1 of the frequency dividing circuit 13 so as to provide predetermined outputs of the frequency dividing stages F1, F2 . . . to the contacts K1, K2 . . . In the embodiment shown in FIG. 2, the output of the first stage F1 is supplied to the contact K1, the output of the stage F2 to the contact K2 etc. The signal G received by the movable contact J is formed into a pulse having a sharp rising waveform in the waveshaping circuit 15 and thereafter is supplied to the gate circuit 7 as a control signal.
If a certain rhythm, for example bossanova, is selected in a rhythm selection circuit 6 with the switch 14 in the stage shown in FIG. 2, eight clock pulses corresponding to one measure provided by the clock pulse oscillator 1 cause the memory 4 to produce a state of output Ma corresponding to maracas in the rhythm of bosanova at the output B1, a state of output Cl corresponding to claves at the output B2. a state of output Cy corresponding to cymbal at the output B3 and a state of output Bd corresponding to bass drum at the output B8 respectively as shown in FIG. 3a.
The signals produced at the outputs B1, B2, B3 and B8 of the memory 4 are applied to the gate circuit 7. The gate circuit 7 is controlled by the output pulse of the waveshaping circuit 15 provided for forming the clock pulse CP into a pulse having a sharp waveform, and produces a pulse having a waveform which is substantially the same as the clock pulse when the output of the memory 4 is 1 . Consequently, when the memory 4 produces the signals shown in FIG. 3a, a percussion instrument sound signal generating circuit 8 is provided at its respective input terminals with a pulse output Ma0 corresponsing to maracas, a pulse output Cy0 corresponding to cymbals, a pulse output Cl0 corresponding to claves and a pulse output Bd0 corresponding to bass drum respectively as shown in FIG. 3b.
Thus, the percussion instrument sound signal generating circuit 8 produces the percussion instrument sound signals corresponding to the rhythm of bossanova.
If the contact of the switch 14 is switched to K1 from the above described state, the signal CP is divided by two in frequency in the frequency dividing circuit 13. Accordingly, a train of pulses G shown in FIG. 3c which consists of every other pulse of the train of pulses CP shown in FIG. 3b is applied to the input of the waveshaping circuit 15 for waveshaping. Hence, pulse trains Ma1, Cy1, Cl1 and Bd1 as shown in FIG. 3c respectively corresponding to maracas, cymbals, claves and bass drum are applied to the percussion instrument sound generating circuit 8 notwithstanding that the memory 4 provides the states of output as shown in FIG. 3a to the gate circuit 7 in the same manner as previously described. Accordingly, the circuit 8 provides percussion instrument sound signals which are equivalent to the percussion instrument sound signals produced by the successive application of the first, second, . . . clock pulses CP to the memory 4 when the switch 14 is switched to the contact K0 except for the signals corresponding to the second, fourth, sixth . . . pulses which are removed therefrom. This output from the circuit 8 forms an anomalous rhythm pattern compared with the rhythm pattern of bossanova stored in the memory 4.
Likewise, if the contact J of the switch 14 is switched to the contact K2, the percussion instrument sound signal generating circuit 8 produces percussion instrument sound signals consisting of signals identical with the percussion instrument sound signals produced by switching the switch 14 to the contact K0 excluding the signals corresponding to the second, third and fourth pulses and the sixth, seventh and eighth pulses, etc. Similarly, various anomalous rhythms are produced by switching the switch 14 to the contacts K3, K4 etc.
According to the present invention, various rhythm patterns which are anomalous compared with a standard rhythm pattern obtained by switching of the rhythm pattern selection switch 14 to the contact K0 can selectively be obtained by switching the switch 14 to a selected contact. Thus, the apparatus according to the invention gives variety and a human touch to the performance of the rhythm playing apparatus by a mere addition of the frequency dividing circuit 13 and a switch 14.
In the foregoing embodiment, various kinds of pulse trains can be obtained as the control signal by modifying the frequency dividing circuit 13 in various ways such as providing a feedback circuit therein. If, for example, a standard rhythm pattern is one including triplets, various rhythm patterns which are anomalous to the standard rhythm pattern can easily be obtained.