Description:
BACKGROUND OF THE INVENTION
This invention relates to an automatic rhythm instrument and more particularly to a novel type of such instrument newly provided with a temporary roll beat performance.
Automatic rhythm instruments heretofore put to practical application are generally provided with a clock pulse oscillator for generating a repetitive basic tempo pulse train having a frequency or time width corresponding to the shortest beat unit (generally, a quaver or semiquaver) for the various rhythm tempos, the oscillator being further followed by a multistage frequency dividing counter chain.
According to the conventional automatic rhythm instrument, a basic tempo pulse train from the clock pulse oscillator is divided in frequency by counter stages exhibiting binary output pulses from the various stages of the counter chain. The pulse trains are conducted through the known rhythm pattern forming circuit including a diode matrix circuit to generate various sets of rhythm pattern pulses such as those of the march, rumba and tango.
The prior art automatic rhythm instrument is only designed to produce sounds derived from various percussion instruments, for example, cymbals, maracas and claves, or ordinary chord or bass sounds or combinations thereof in exact timing with tempos of any desired one or more of the aforesaid rhythm pattern pulses.
The object of this invention is to provide an automatic rhythm instrument capable of effecting a rhythmic performance of far greater variety than has been possible with the conventional rhythm instrument.
SUMMARY OF THE INVENTION
An automatic rhythm instrument according to a preferred embodiment of this invention is characterized in that it is so designed as to drive its various rhythm sound sources by any desired one of a plurality of repetitive pulse trains each having a predetermined frequency or time width which are used in encoding various sets of rhythm pattern pulses.
An automatic rhythm instrument of the aforementioned arrangement has the advantage of effecting a performance of far greater variety than the conventional automatic rhythm instrument which is so arranged as to cause its rhythm sound sources to be energized only by the above-mentioned various sets of ordinary rhythm pattern pulses.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic circuit diagram of an automatic rhythm instrument according to an embodiment of this invention; and
FIG. 2 is a schematic circuit diagram of a modification of the rhythm instrument.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, reference numeral 11 denotes a clock pulse oscillator of free-running oscillation type such as an astable multivibrator provided, for example, with a frequency control element 12. The clock oscillator 11 is so adapted as to generate a repetitive basic clock pulse train having a frequency or time width corresponding to the shortest beat unit (e.g., a semiquaver) required to produce the later described various sets of rhythm pattern pulses. Output pulses from the clock oscillator 11 are conducted to a multistage frequency dividing counter chain 13, which comprises, in this example, four stage binary circuits (flip-flop circuits) 13 1 , 13 2 , 13 3 and 13 4 cascade connected such that the output line of each stage is connected to the input line of the immediately following stage. These binary circuits 13 1 to 13 4 are operated with frequencies corresponding to 1/2, 1/4, 1/8 and one sixteenth of those of output pulses from the clock pulse oscillator 11 (namely, 2-, 4-, 8-, 16-times length periods) and are respectively provided with two output lines a--a, b--b, c--c and d--d so as to produce two output pulses corresponding to the binary ONE and ZERO which are different by 180° in phase. The output pulses from the binary circuits 13 1 to 13 4 are conducted into a rhythm pattern pulse encoder 14 of the later described arrangement to be converted into various types of rhythm pattern pulse trains such as for waltz, march and rumba.
As is well known to those skilled in the art, the rhythm pattern pulse encoder 14 is provided with diode matrix connected to respective two output lines of the respective binary counters 13 1 to 13 4 , and with AND logics and OR logics as is known in this field.
Various sets of rhythm pattern pulse trains obtained from the rhythm pattern pulse encoder 14 of the above-mentioned arrangement pass through the corresponding normally closed switches SW 1 to SW n provided, if required, and a rhythm selector switches 15 selectively operated by a player prior to performance, so as to be supplied as trigger signals to the preselected ones of a plurality of rhythm sound sources R 1 to R n such as those of the cymbals, maracas and claves. These rhythm sound sources R 1 to R n are connected to a loud-speaker 18 through a common amplifier 17.
This invention is characterized in that temporary roll beat circuit or a fast repetitive trigger pulse introducing path 21 of the later described arrangement is provided between the input lines of the rhythm sound sources R 1 to R n and the desired ones of the output lines of the clock oscillator 11 and/or the binary counters 13 1 to 13 4 . Said temporary roll beat circuit 21 comprises a plurality of normally open switches SW 11 to SW 1n , having, for example, the movable contacts connected to the input lines of the rhythm sound sources R 1 to R n ; and a changeover or selector switch SW 31 having a single movable contact connected to the common connection 20 of the fixed contacts of said switches SW 11 to SW 1n through a normally open switch SW 21 , provided,if required, and having three stationary contacts connected to the output line of the clock pulse oscillator (i.e., the input line of the first stage binary counter) as well as to the output lines of the first and second stage binary counters 13 1 and 13 2 . The stationary contacts of the selector switch SW 31 are selectively closed by said single movable contact. The normally closed switches SW 1 to SW n are gang operated with the normally open switch SW 21 . (this constitutes a temporary roll beat introducing switch).
There will now be described the manner in which a performance is made on the automatic rhythm instrument arranged as described above. First, with the normally open switch SW 21 and normally closed switches SW 1 to SW n left intact, the rhythm selector switch 15 is operated to select a certain desired rhythm performance. Then the preselected one or more of the rhythm sound sources R 1 to R n are actuated in accordance with the rhythm pattern pulse trains from the rhythm pattern pulse encoder 14, thereby producing an ordinary automatic rhythm performance.
Next, with the desired one or more of the normally open switches SW 11 to SW 1n of the aforesaid temporary roll beat circuit 21 closed and the single movable contact of the selector switch SW 31 connected to the desired one of the three associated stationary contacts, the normally open switch SW 21 is closed and the normally closed switches SW 1 to SW n are opened. Thus the preselected one or more of the rhythm sound sources R 1 to R n are now actuated for performance directly by the repetitive output pulse train delivered from the clock pulse oscillator 11 or from the first or second binary counter 13 1 or 13 2 according to the selection by the switch SW 31 .
The rhythm performance obtained by the pulse train derived from the temporary roll beat circuit 21 is entirely different from the ordinary rhythm performance in accordance with the encoded rhythm pattern pulses from the encoder 14, and simulates such performance as the roll beating on the drum. Thus this invention realizes a novel type of automatic rhythm instrument attaining a rhythm performacne of far greater variety than has been possible in the past.
FIG. 2 is a schematic circuit diagram of an automatic rhythm instrument according to a modification of this invention. According to this modification, rhythm sounds from a plurality of rhythm sound sources R 11 to R 1n are delivered through their keyers 31 1 to 31 n . As illustrated in FIG. 2, the rhythm sound sources R 11 to R 1n are placed (connected) to other positions than those in the embodiment of FIG. 1, and instead the keyers 31 1 to 31 n take the original positions of such sources in FIG. 1 and are connected to the output side of the rhythm selector switches 15. In FIG. 2 the normally closed switches SW 1 to SW n of FIG. 1 are eliminated. The elements of FIG. 2 which are the same as those of FIG. 1 are denoted by the same numerals and the description thereof is omitted. An automatic rhythm instrument arranged as shown in FIG. 2 realizes the performance effect as follows. Namely, where the preselected one or more of the keyers 31 1 through 31 n are to be triggered by desired rhythm pattern pulse trains from the rhythm pattern pulse encoder 14 in accordance with the preset state of the rhythm selector switches 15, the fast repeating pulses are added through the aforesaid temporary roll beat circuit 21, whereby the fast beating performance by such rhythm sounds determined by the switches SW 11 through SW 1n is added to the normal automatic rhythm performance.