Of a Master Performance

I'm listening to an amazing recording right now and its story is even more amazing. It's of Keith Jarrett's Jazz piano concert given in Colgne in 1975 and the story according to Wikipaedia is fascinating and goes something like this.

Preliminaries to the concert were not auspicious. The concert was organized by 18 year-old Vera Brandes, Germany’s youngest concert promoter. At Jarrett's request, Brandes had selected a Bösendorfer 290 Imperial concert grand piano for the performance. However, there was some confusion by the opera house staff and instead they found another Bösendorfer piano backstage - a much smaller baby grand - and assuming it was the one requested placed it on the stage. Unfortunately, the error was discovered too late for the correct Bösendorfer to be delivered to the venue in time for the evening's concert. The piano they had was intended for rehearsals only and was in poor condition and required several hours of tuning and adjusting to make it playable.The instrument was tinny and thin in the upper registers and weak in the bass register, and the pedals did not work properly. Consequently, Jarrett often usedostinatos and rolling left-hand rhythmic figures during his Köln performance to give the effect of stronger bass notes, and concentrated his playing in the middle portion of the keyboard. Jarrett arrived at the opera house late in the afternoon and tired after an exhausting long drive from Zurich, Switzerland, where he had performed a few days earlier. He had not slept well in several nights and was in pain from back problems and had to wear a brace. After trying out the substandard piano and learning a replacement instrument was not available, Jarrett nearly refused to play and Brandes had to convince him to perform as the concert was scheduled to begin in just a few hours.
The concert took place at the unusually late hour of 11:30 PM following an earlier opera performance. This late-night time slot was the only one the administration would make available to Brandes for a jazz concert - the first one ever at the Köln Opera House. The show was completely sold out and the venue was filled to capacity with over 1400 people at a ticket price of 4 Deutsche Marks.
The playing was improvised. In other words it all came straight out of his head. The concert was a critical success and the recording remains the best selling album of any jazz soloist of all time.