Over the past 40 years, Keith Jarrett has come to be recognized as one of the most creative musicians of our times universally acclaimed as an improviser of unsurpassed genius; a master of jazz piano; a classical keyboardist of great depth; and as a composer who has written hundreds of pieces for his various jazz groups.

This record-breaking album still gets a chilly reception from some jazz fans. But the inspiration behind its inception lives on. If you've ever been curious over the fuss jazz piano fans make over Keith Jarrett, this album is the reason. This more than 30-year-old concert, spectacularly recorded by ECM owner/svengali Manfred Eicher, remains the fresh jewel it was the day it came out.

Consisting of one long improvisation that Jarrett played on January 24th, 1975, in the opera house in Köln, Germany, and which was later divided into four unnamed parts to fit on LP, it is one of the most extraordinary solo virtuoso performances ever recorded. The ideas literally pour from his fingertips, his crisp technique creates melodic figures and lines that intertwine and intersect; his speed matched only by his lyricism. His occasional sighs and joyous exclamations only add to the sense that he too was surprised at the mass of music gushing out of him. The raw rainbow of emotional and musical colors here is nearly blinding.

The concept of music being prismatic, that it can mean and be almost anything depending upon what the listener brings to it from his or her own experience, may have begun right here. Forever astonishing after all these years.