In today's Sound Perimeter, we learn more about string quartets, a chamber music group that consists of four string musicians: two violin players, one viola player and a cellist. The string quartet has been perhaps the most recognized chamber ensemble since the 1750s when classical composer Franz Joseph Haydn started writing for that instrument combination. String quartet also denotes the name of the pieces written for that ensemble. Featured are Joseph Haydn, Quartet in B flat major, the Dover Quartet, the Laurie Anderson, Shutter Island, Kronos Quartet, the Commodores, Brick House, and Belmont University Jazz String Quartet.