I thoroughly enjoyed this, watching it again and again. The music itself is superbly arranged, performed, mixed, etc. The editing is superb, flashing back and forth through time and space with ease and power. The story is a blend of the shining power of artistic innovation, together with the darkness of racism, narcotics, personal life tragedy, the jeopardy of artistic creation, and mental illness. The acting is superb and deeply engaging. Not a simplistically "enjoyable" picture, but an important one to see on many levels, and my personal best picture of the year.
