Tunable electrical musical instrument

In an electronic musical instrument for playing scales including those with more than twelve tones per octave and those with unequal temperament, a master programmable unit comprising:

• oscillator means for providing a fixed reference frequency signal;
• and
• a plurality of individually programmable sections, each said programmable section having capability for producing twelve tones per octave independently of any other programmable section, and each including
• at least twelve divider chains connected to said oscillator means for receiving said fixed reference frequency signal and for producing simultaneously a first twelve distinct signals from said reference frequency signal, the divisor number of each said divider chain being adjustable and the divisor number of one of said divider chains being related to the divisor number of any second one of said chains by a factor greater than one and less than two,
• program means connected to said frequency divider chain for changing the divisor numbers of individual chains to vary the frequencies of said first twelve distinct signals,
• octave divider means connected to receive said first twelve distinct signals from said twelve divider chains and to produce therefrom at least a second twelve signals, each of the second twelve signals having a frequency related to the frequency of one of said first twelve signals by a multiple of two, and said octave divider means having an output for each of said second twelve signals,
• reproducing means for receiving and reproducing signals applied thereto, and having a multiplicity of output terminals, and
• switching means having at least twelve key switches, each key switch connected to an output of said divider means, for coupling the signal from said divider means output to said reproducing means.