Perhaps realizing that Celebrity nearly collapsed under the unbearable impersonation by Branagh, Allen has created a more complex doppelgänger for himself in the form of Sean Penn, playing a fictional 1930s jazz guitarist by the name of Emmett Ray. Emmett is a genius with music but a loser in love, using his self-proclaimed status as an artist as an excuse to behave with loutish abandon. Continually and amusingly haunted by the fact that he is only the world's second-greatest guitarist (after Django Reinhardt), Ray stumbles drunkenly through life like a soft-hearted pit bull, and Allen and other artists provide onscreen, documentary-like commentary on Ray's downfall.
Even though Penn's peerless craft allows him to move here with the sly, remarkable balance that has previously bolstered unseemly characters, Allen doesn't completely reward you for putting up with Emmett's boorishness. He takes too long to tell us what we already know. When Emmett romances a mute waif (Samantha Morton, doing wonders in a role whose Freudian implications I'll leave to others), it doesn't take Allen's genius to tell us he'll be sorry when he breaks her heart. The film shimmers under the spell of Santo Loquasto's production design and the crisp nostalgia of Zhao Fei's cinematography, but says nothing more, tellingly, than that art is a beautiful but poor mistress.
What distinguishes Sweet and Lowdown is its plaintive insistence, the deceptively lazy melancholy that occasionally breaks through and -- in perfect pitch with the music -- suggests that Allen realizes what a glorious mess he's made of both life and art.
