"Headin' for Broadway," a piddling chronicle of four young hopefuls who converge on New York to audition for the chorus line of a new show, suggests that the mini-meteroric career of Joseph Brooks, the most preposterous multiple-threat filmmaker since Tom Laughlin, is plunging back to obscurity.

The modest unexpected success of "You Light Up My Life," Brooks' maiden effort as writer-director-composer, encouraged the laughable hubris of "If Ever I See You Again," in which Brooks miscast himself as an eligible, vituous heartthrob and provoked mirthful gagging from Hollywood to Hicksville.

Lacking Brooks' starring presence, "Headin' for Broadway" isn't remotely as outrageous or diverting as its predecessor. Indeed, it's such a negligible account of the traditional struggle to make the Big Time that one doubts if the movie will survive theatrically longer than a week.

"Headin' for Broadway" opened stone cold at area theaters over the weekend. The distributor, 20th Century-Fox, hadn't publicized the opening. Coming out of a suburban triplex that had sheltered the film, I met the district manager for the theater chain. He revealed that three scheduled performances had failed to draw a single customer. With five patrons in the house, the showing I caught had been extravagantly well attended.

Brooks fails to sustain cliched human interest about the prospects of Ralphie (Paul Carafotes), a Travoltaesque hoofer from Philadelphia; Carrie (Terri Treas), a bland songbird from amateur theater in Somewhere, Ohio; Fast Eddie (Rex Smith), a golden boy from L.A. returning for another shot at Broadway after three previous setbacks; and Valarie (Vivian Reed), a striking black dancer and blues singer whose background consists of fleeting glimpses of presumably formative years with the church choir. Although Valarie would seem to possess the most impressive performing credentials in this quartet, she remains the least integrated and appreciated character. The vacuous Carrie is supposed to entice both street-kid Ralphie and beachboy Eddie, but the source of her allure must be Brooks' little secret. Or big misconception.

Terri Treas' face is such a limited emotional instrument that it appears to be asking too much to ask for merely token reactions. When an overardent Ralphie pleads, "Whadda ya feel about me?," Carrie responds by trying to knit her brow thoughtfully. But it refuses to knit: Treas presents a facade so placid that it defies pictuesque rippling.

The neglect of Valarie and the superficial interplay between Ralphie, Carrie and Eddie provide the skimpy connective tissue between audition sequences, a familiar but always intriguing process in which hundreds of aspirants are pared down to a supposedly lucky dozen. The presiding choreographer, Jay, is portrayed by the film's choreographer, Gene Foote, who suggests a fey contender to the crowns of Bob Fosse and Michael Bennett.

A silly but engaging presence, Foote is given to breathlessly urgent remarks about his seemingly unremarkable dance routines. Unveiling his First Elimination exercise of the producer, Foote confides, "If they can do this, they can do anything. I just hope it's not too dirty." Not to worry, sweetheart. As final auditions approach, he reveals that "I did find two good boys. I only hope they can do that boys' combination. It's a killer." Not half as killing as his dialogue, I'll bet.

Brooks can't finesse the question that haunts his threadbare pilot: Why single out the aspirants he elects to single out? One keeps noticing more interesting faces and skills among the performers who surround the nominal leads. At the same time, it's difficult to sustain the lyrical side of a backstage musical drama on tunes as strenuously depleted as the ballad Joe Brooks composes.

The movie does make you wonder if there ever will be a film version of "A Chorus Line." After false starts with Michael Bennett and then Mike Nichols as prospective directors, the show has been farmed out to Polygram (the new incarnation of Casablanca Films and Records) by Universal, which acquired film rights for a reported $5 million in 1975. Presumably, an astute adaptation would utilize the same "classic" format bungled by Brooks.

However, the feebleness of "Headin' for Broadway" may erode whatever incentive still exists for transposing "A Chorus Line" to the screen. Negligible as it is, Brooks' little clinker may have the makings of spoiler.