The Kronos Quartet is an American string quartet based in San Francisco. It has been in existence with a rotating membership of musicians for 50 years. The quartet covers a very broad range of musical genres, including contemporary classical music. More than 1,000 works have been written for it. History. The quartet was founded by violinist David Harrington in Seattle, Washington. Its first performance was in November 1973. Since 1978, the quartet has been based in San Francisco, California.
https://en.wikipedia.org/wiki/Kronos_Quartet