A Rainbow in Curved Air is the third album by experimental music and classical minimalism pioneer Terry Riley. Through the use of overdubbing, the composer, a keyboard virtuoso, plays all the instruments on the title track: electric organ, electric harpsichord (Rock-Si-Chord), dumbec (or goblet drum), and tambourine. The combination of the one-man-band overdubbing, electronic instruments, and improvisation made for a unique and influential recording, a defining psychedelic work of the 1960s, enhanced by its cover art and the peace poem that constitutes the liner notes.