A musical instrument is proposed with the following elements: a tone generator capable of reproducing the attack and decay transients and the steady state of the tones of conventional musical instruments with correctly proportioned partials, the frequencies of those associated with one note being integral multiples of a low frequency; keyboards sensitive to the speed with which a key is depressed and the distance to which it is depressed, so that the intensity of each note may be expressively controlled at all times; a unit for the controllable generation of massive choruses from solo voices by producing narrow, complex spectra about each partial; an intensity control unit; environment modification equipment to alter the apparent size of the room within which the music is heard and the apparent size and location of the source, and to distribute and diffuse the sound; a preset unit in which sequences of timbre, vibrato, choral massiveness, environmental characteristics, and other factors may be established before performance and quickly and easily called forth during performance. The features include tones of familiar character and quality, realistic choral effects, expressive touch, environmental control, flexibility, and ease of playing. Numerical results are appended to demonstrate the feasibility of construction.