The Köln Concert
The Köln Concert is a live recording of solo piano improvisations performed by Keith Jarrett at the Opera House in Cologne on 24th January 1975. The double-vinyl album was released in the autumn of 1975 by ECM Records and went on to become the best-selling solo album in jazz history, and the all-time best-selling piano album with sales of more than 3.5 million. (Wikipedia)