Charlie Parker attracted young musicians like a magnet. Among them was trombonist Jimmy Knepper, who, at a time when tape recording was a brand-new thing, captured Bird in flight one winter night in Manhattan. He soared, and when Charles Mingus heard the music years later, he issued it as the first release on his new Jazz Workshop label. Since then, many private recordings of Parker have been made public. This was one of the first, and remains one of the best, a precious musical document.