The spectacle offers surprisingly little historical information about the emergence of jazz or Morton's era - other than mentions of W.C. Handy and others who try to deny Morton his glory - relying instead on Morton's character and biography. This entails not a little psychologizing; Jelly, we learn, was born into a pretentious, ultragenteel Creole family who spoke French and danced minuets - and who eventually cast him out of the gilded cradle when he took to hanging out with the wrong (dark) kind of people (they turned out to be "right" for his musical development, however). The implication is that this rejection damaged him, causing him, paradoxically, to dole out the same snobbism that hurt him so badly.
If there's a problem with this musical, it's not that Morton is an unsympathetic character, it's that we don't get a relationship to hang our hat on until late in a very long first act. His affair with Sweet Anita (played with fire by Nora Cole, an original cast member) and the subsequent triangular tensions among him, Anita, and his sidekick, Jack, tear at your heart, but until then, you feel oddly detached from the story.
But you don't care about any of that when the cast gives it up. Young Jelly (Savion Glover) tearing it up alongside Maurice Hines is a joy to behold, and the Hunnies - a three woman Greek chorus dressed in black bodices - can make anyone weak in the knees.
Medea, the Musical runs through July 29 at the Lorraine Hansberry Theater in S.F.; call 436-0806. Jelly's Last Jam runs through July 30 at the Golden Gate Theatre in S.F.; call 776-1999.