Seventeen Coils
Seventeen Coils is a configuration of seventeen lightweight coil springs attached to a styrofoam soundboard. They’re sounded by plucking longways — using a fingernail to pull and release one of the coils not sideways but in the direction of the length of the spring. The styro board is mounted perpendicular to the springs, which allows the longitudinal movement to transmit efficiently to the board. For a fuller discussion of this instrument and of the acoustics of coil springs in general, see this essay.
In the audio clip below, Seventeen Coils is joined by The Other Side, Square Boos, Air-Air and some percussion instruments.