19. The computer-readable storage medium of claim 17 , wherein the set of music elements identify components of the music contribution at multiple time intervals within the music contribution.
19. The computer-readable storage medium of claim 17 , wherein the set of music elements identify components of the music contribution at multiple time intervals within the music contribution. 20. The computer-readable storage medium of claim 19 , wherein the components of the music contribution are identified relative to a recorded performance.