"The First Nudie Musical," which opened Wednesday at the Avalon I, the K-B Fine Arts and the K-B Cinema 7, is not the first nudie musical, but it may well be the last word in cinematic piffle.

It's a cheapo takeoff on porn flicks and movie musicals that might have been expected to die unheralded of its own terminal ineptitude. Incredibly, though, it prompted a slew of adoring reviews in New York, not just from the chronic ravers but from people like Joseph Gelmis, William Wolf and others who might have been expected to know better. Thus spared from oblivion, it is making the rounds - but don't say you weren't warned.

The picture was made for less than $20,000, a fact which its admirers seem to regard as an automatic badge of distinction. There's a difference, though, between lack of frills and lack of talent. In this case, it's hard to see what is supposed to be compensating for the crude photography, bad editing, sophomoric story and forgetable music. Sample dialogue: "You don't have anything against oral sex, do you. John?" "Oh, no, I like to talk about sex as much as the next fellow." Sample production number a dance with the females nude, the males dressed as vibrators.

The filmmaker is 29-year-old Bruce Kimmel, who wrote the screenplay, the music and lyrics, and co-directed with Mark Haggard. he is also acts in the film and the picture's one real touch of comic artistry is his performance as an aspiring but boneheaded director. It's just not enough of a redeeming value, though. The ads, rated "R" for "raunchy, racy and riotous." It should have been, "S" for sloppy, scabrous and soporific.