This is a film adaptation of the Broadway musical about a singing trio with a suspicious resemblance to The Supremes. It is top-level entertainment with rousing songs and some first-rate performances that are already generating Oscar buzz.

Jamie Foxx does a fine job playing the brilliant but unscrupulous manager who masterminds the group’s rise to fame and fortune. Beyoncé Knowles delivers a workmanlike performance in the thankless role of the singer who get the lead because her looks and voice have a bland commercial appeal (in other words, the Diana Ross character.)

But I was astonished by Eddie Murphy’s performance as James ‘Thunder’ Early, the charismatic but doomed R&B singer. This seems a step beyond anything that Murphy has done in the past.

And newcomer Jennifer Hudson seems to be drawing the most attention as the singer with true Soul. She dominates every scene she is in, generally grabbing it by the throat and slamming it to the ground.

Yet in spite of the movie’s great entertainment value, I was left with a frustrated feeling that this is not as great as it might have been. This is definitely a “musical”, but not a “musical comedy”; there is nothing comic about this material. It is a dark story of disillusionment and betrayal, and at that level it does not fully work, at least not for me. I’m not really sure why.

A lot of the dialog that was sung in the original Broadway production is spoken in the move, and that may be a mistake. It makes the inevitable moments all the more jarring when a character, shocked by some devastating revelation, responds by bursting into song. That kind of thing works better with comedy than with drama. Would it have worked better if they had sung all the lines, in the manner of grand opera? Perhaps, but it would also have greatly reduced the commercial appeal of the movie. Since the story is largely about the conflict between success and artistic integrity that makes an ironic sort of sense.