The Köln Concert is a concert recording of solo piano improvisations performed by Keith Jarrett at the Opera House in Cologne (German: Köln) on January 24, 1975. The double-vinyl album was released in 1975 by ECM. It became the best-selling solo album in jazz history and the best-selling piano album with sales of more than 3.5 million. Subsequent to the release of The Köln Concert, Jarrett was asked by pianists, musicologists and others to publish the music. For years he resisted such requests since, as he said, the music played was improvised “on a certain night and should go as quickly as it comes”. In 1990, Jarrett finally agreed to publish an authorized transcription but with the recommendation that every pianist intending to play the piece should use the recording itself as the final word. A transcription for classical guitar has also been published by Manuel Barrueco.