5 Instruments Terry Riley Layered on "Rainbow"

Electric organ Riley used an electric organ as the foundational layer for the track.

Two electric harpsichords He overdubbed a Baldwin and an RMI Rock-Si-Chord, adding contrasting tonal textures.

Dumbec This goblet drum provided a percussive, rhythmic anchor.

Tambourine The tambourine added a bright, shaking accent to the mix.

One-man orchestra Riley played all these instruments himself through overdubbing, creating a minimalist ensemble sound.