Is the voice on ''Forever Your Girl'' Paula Abdul's? -- A new lawsuit casts doubt over just how much of the pop queen's vocals are her own

When a new Paula Abdul single, ”Rush Rush,” is released on May 2 from her upcoming album, Spellbound, fans may be watching the video siren’s lips more closely than her legwork. Caught up in the biggest voice-over outcry since Milli Vanilli were revealed as secret lip-synchers, Abdul’s record company has been sued by a studio backup singer who insists her voice was used in three lead vocals on Abdul’s smash 1988 debut album, Forever Your Girl. And if the plaintiff wins, the floodgates may be opened for all backup singers to sue to determine their contributions to a star’s songs.

Yvette Marine, a session singer and ex-member of Rick James’ Mary Jane Girls, filed the million-dollar lawsuit against Virgin Records earlier this month, claiming her voice was merged with Abdul’s on the songs ”Opposites Attract” (which won a Grammy for short-form video for Abdul), ”I Need You,” and ”Knocked Out.” Virgin and Abdul have denied the charge, but Marine’s attorney, Steven Ames Brown, says, ”This is Vocalgate — they wanted her to join in a cover-up,” contending that Virgin offered her hush money to keep quiet about the session work. (Brown sued and settled out of court with RCA Records last year on behalf of ex-Weathergirl Martha Wash for vocals on Black Box’s Dreamworld album.)

The lawsuit by Marine, who was credited as a background vocalist on Forever, alleges that Virgin deliberately combined her ”pilot track” or ”guide vocal” with Abdul’s lead track in the final mix and passed it off as one voice. Marine says she was also asked to enhance Abdul’s ”I Need You,” and wore headphones that piped in Paula’s vocals. ”I was listening to her and matching her,” says Marine. At a press conference, however, Virgin’s Jeff Ayeroff submitted a sound analysis of ”Opposites Attract” conducted by University of California music professor Fredric Lieberman, who says, ”It remains possible, though I believe highly improbable, that a small percentage of Yvette’s pilot track was blended or bled into some sections of the lead vocal mix, but if so it is imperceptible.”

The use of guide vocals by singers is not unusual. Besides blending two vocals together, common studio tricks include applying processors and harmonizers to enhance an audio track. But Virgin maintains the only technology used to sweeten Abdul was double-tracking — recording the singer’s voice twice to strengthen its timbre. ”Paula’s a really good singer, and that’s why this thing pisses me off,” says L.A. producer Don Was, who worked on Spellbound.

Curious fans will be able to decide for themselves in August, when Abdul begins her first headlining tour. For a year and a half, she has been training with Shirley MacLaine’s vocal coach — even jogging with him to learn how to project while dancing. Does that mean her show won’t have those canned vocal assists used by dance queens from Madonna to Janet Jackson? ”I can’t say,” says a source close to Abdul. ”But one thing’s for sure — you won’t see her singing alone with just an acoustic guitar.”