One of the greatest piece of music of all time is the fruit of a blatant mistake: Keith Jarrett's Köln concert. Instead of the required Bösendorfer 290 Imperia

One of the greatest piece of music of all time is the fruit of a blatant mistake: Keith Jarrett's Köln concert. Instead of the required Bösendorfer 290 Imperial, the organization team brought a smaller and badly tuned piano on stage. Jarrett - who was a bit of a diva at times - initially refused to play, but gave in, and the recording is the thing of legends.