Shaker Loops is a 1978 composition by American composer John Adams, originally written for string septet.
This version was first performed in April of that year at Alice Tully Hall, New York, by the American Composers Orchestra, conducted by Michael Tilson Thomas.
Shaker Loops began as a piece called Wavemaker in which Adams tried to emulate the ripple effect of bodies of water in his music.
The piece was a commercial failure, but Adams kept the idea of repeating loops of oscillations on string instruments.
[1] Several recordings of the string orchestra version have been released on CD, including one by Edo de Waart and the San Francisco Symphony Orchestra for Philips Records.