There is something to be said for a work ethic, and filmmaker Woody Allen has been saying it, doggedly and often eloquently, since the mid-1960s. Allen's annual 'fall projects'-low-key productions generally shot in New York-are part of cinema folklore. But turning out a movie on a yearly basis can be arduous, and Allen's output in the 1990s has been arguably a bit disappointing-until now, with the arrival of Sweet and Lowdown, a dark comedy about show business every bit as brilliant as Zelig and Broadway Danny Rose.

As Zelig portrayed a bizarre chameleon and Danny Rose a small-time showbiz manager, Sweet and Lowdown chronicles the adventures of Emmet Ray (Sean Penn), a fictional American jazz guitarist of the 1930s, considered a musical genius second only to the legendary Django Reinhardt. Django is an artist so daunting that Emmet, upon meeting him twice in Europe, fainted both times. But Emmet is also a cad, hopelessly vain, heartless toward women, and not particularly kind to anyone else. Still, when Emmet picks up his guitar, he plays so brilliantly that it seems as though all could be forgiven.

Sweet and Lowdown opens to a chorus of witnesses a la Zelig, led by Allen and jazz maven Nat Hentoff, who attest to Emmet Ray's musical gifts and foibles, a generally humorous device which will resurface throughout the movie. Emmet's various showbiz stunts-he stole an alarm clock from Hoagy Carmichael and once attempted a stage entrance riding a half-moon down from the ceiling of a nightclub, with disastrous results-are genially recalled, but the dark, idiosyncratic side of Emmet provides an ongoing pattern. For all his artistic genius, he seems never happier than when he is abusing women, morosely watching trains, and shooting rats with a .45 at the city dump.

Emmet's liaison with Hattie (Samantha Morton), a sweet-natured deaf-mute laundress he meets on the boardwalk at Atlantic City, offers, however briefly, the possibility that he can emerge from his self-obsession. But, devoted as Hattie is to him, he cruelly dismisses her as a 'mute half-wit.' As Emmet grows more heartless, his personal philosophy becomes even darker. 'Sooner or later,' he observes, 'everybody's dreams go up in smoke.' Emmet goes on to marry a writer named Blanche (Uma Thurman), who, as fate would have it, can be just as unfaithful as Emmet, but with mob connections.

Penn delivers a richly textured comic performance and proves to be a surprisingly credible guitar player. As for Morton, she is nothing short of wonderful in a role-strange as it may seem-that is reminiscent of Harpo Marx. Top technical credits should go to Santo Loquasto's evocative production design and the luminous cinematography of Zhao Fei, whose credits include Zhang Yimou's Raise the Red Lantern. Sweet and Lowdown probes a darker vein than many a Woody Allen movie, but it's also a richly comic piece which can join the ranks of this filmmaker's very best work.

--Ed Kelleher