THE BLUES BROTHERS -- AMC Carrollton, Aspen Hill, Center, Jenifer, K-B Langley, Marlow, Reston, Springfield Mall.

The initial camera angle in " the Blues Brothers" focuses on broad-beamy John Belushi, from behind and slightly below. Not his best feature, but the most appropriate for the movie.

It takes brass in to turn the blues into the blahs, but brass is one thing Belushi and Dan Aykroyd have aplenty. How else could they have stretched an outworn "saturday Night Live" skit into a 2 1/2-hour, $30-million movie that earns its tantalizing R-rating with a splattering of extraneous four-letter words?

Surely not with the storyline, in which R&B disciples Joliet Jake (Belushi) and Elwood (Aykroyd) Blues try to raise $5,000 for the nun-run orphanage where the grew up by arranging a big blues concert. In this holy cause, they hoax, coax, confiscate and casually eliminate everything from the American Nazi Party to the Illinois National Guard, all the while dodging the flame-throwers and bombs of a nysterious scarlet-nailed woman. Jake and Elwood leave a trail of borken police cars like a maraschino massacre.

It's supposed to be a tongue-in-cheek tribute to the redemptive power of the blues, but unfortunately the two stars are completely outclassed. Surrounded by some of the finest black bluesmen, soul singers and Muscle Shoals swampers in the business, Aykroyd and Belushi are so inept that the joke cuts the wrong way: Their clumsy shuffling and wailing seems insulting.

Besides, two while imitators are making all the money out of this salute to an integrally black idiom. Again.

Nevertheless, much of the movie -- the part that pans away from the Brothers -- is beatified by the feature players. Cab Calloway, as the orphange janitor who gave the boys their first taste for music (and for the sunglasses they never remove), steals the concert scene blind with a white-tails reprise of "Minnie the Mocher."

Aretha Franklin is a soul-food restaurateur, while John Lee Hooker cooks all too briefly out on the sidewalk. James Brown, pastor of the soul-fullest congregation in Calumet, Illinois -- James Cleveland's choir, with a cameo'd Chaka Knan -- reveals the holy blue light unto the just-paroled Joliet Jake, and music-store-owner Ray Charles gets religion at the ivories of a second-hand electric piano.

Writers Akyroyd and John Landis have taken neurotic shots at all the sophomoric sterotypes: calling the head of the orphanage "the Penquin" (her "real" names is Sister Mary Stigmata); painting the C&W musicians rednecks; implying the Nazi Leader (henry Gibson, in an eerily distateful performance) and his sidekick have a homosexual relationship.

Gotta pay your dues if you wanna sing the blues, but "The Blues Brothers" comes very cheap.