The latest issue of Jazzwise (#157, October 2011) includes an interview with Keith Jarrett by Stuart Nicholson. An excerpt is available on jazzwisemagazine.com:

Even Jarrett himself was taken aback at what he had achieved when he listened to the concert recording for the first time. “Even though I did it, a completely improvised, structured arc of music that has one of the most beautiful endings I have ever done, it still blows my mind,” he reflects. “I know I did it, but there is no way in the world I can say how I did it. I can remember it felt – I won’t say easy – but somehow it was less stressful. That is why I immediately called Manfred from the airport and said ‘Whatever plans we have we’re going to scrap them and release this first’. And he knew it was serious because he never got a call from me from the airport!”