Pulsato is generated by the acoustical mixing of sounds emitted from two frequency shift channels. In one channel a musical or other signal is frequency shifted upwardly by several Hertz, and in a second channel the frequencies are shifted downwardly by a like amount. The listener perceives a pleasing pulsato effect at a frequency equal to the sum of the frequency deviation introduced in the two channels. In another embodiment, a third channel reproduces the musical signal unshifted in frequency. The sounds emitted from the frequency shift channels interact with the audio output from the third channel to produce a pulsato having a frequency equal to the frequency shift of either channel. As defined herein, ''''pulsato'''' is a term meaning cyclic variation of an otherwise relatively constant component or components of music or musical tones at the rate of from five to eight cycles per second. If the only varied component is frequency characteristic of the tone, then the pulsato is vibrato. If the only varied component is amplitude, then the pulsato is tremolo. Other musical components may be varied to produce pulsato.