Martha Wash Gets Her Form Back : Pop music: The singer’s voice but not face appeared on the Black Box videos. But she’ll perform tonight at Details.

When the act billed as Black Box takes the stage at Details dance club in downtown Los Angeles tonight, fans expecting the slim model who appeared to be singing hit songs in the videos and in concerts by the group will be surprised, to say the least.

The voice will be the same as the voice on Black Box’s “Everybody Everybody” and “I Don’t Know Anybody Else,” and the backing tracks will be the same. But the face and form seen by the audience will belong to Martha Wash, a woman who once sang in a duo called Two Tons o’ Fun.

Oh--and there’s another difference between Wash’s show and the ones put on by Katrin Quinol for Black Box: Wash will not be lip-syncing.

The San Francisco native, who gained cult status in the gay disco scene in the early 1980s as part of the Weather Girls with the song “It’s Raining Men,” was thrust into the glare of mainstream media attention last month when the Milli Vanilli scandal sent reporters scurrying for examples of artists whose voices had been appropriated by producers and lip-syncing models.

Wash, who at the time was in the process of suing three record labels for allegedly distributing albums and music videos that featured her voice while crediting other women as the singers, seemed to be made-to-order. In addition to Black Box distributor RCA, she was suing the group Seduction’s record label A&M;, and Columbia Records, for whom the producers of Seduction had made records under the name C&C; Music Factory.

Wash was the singer on C&C; Music Factory’s hit “Gonna Make You Sweat” and Seduction’s “You’re My One and Only True Love.” But it was a Black Box concert that really got to her.

“When Black Box was in New York, I saw their show, and she was standing up there lip-syncing to my music,” the soft-spoken singer said this week, referring to the group’s on-stage front woman Quinol.

“The patrons at the club were quite upset because they knew my voice--I had performed at that club many times before,” Wash said by telephone from New York. “Some of them kind of walked away from the stage area, and there were people trying to talk to me, saying, ‘I’d recognize your voice anywhere. How could she get up there and do that?’ ”

Thanks in part to the publicity, Wash’s troubles seem to be heading toward a resolution. She has signed an eight-year, eight-album contract with RCA and is in settlement talks with A&M.; Her suit against Columbia was filed Monday.

In Los Angeles on the second stop of an eight-city tour--on which many club owners have billed the performer as Black Box, with Wash’s name in small print on the tickets and advertisements--Wash plans to limit her performance to songs by Black Box, Seduction and C&C; Music Factory. The idea is to establish herself as the singer to the dance-club audience that made the songs hits.

Then, she figures, she will have an audience on which to try new music and old hits.

For someone who feels thrice betrayed by the music industry, Wash displays an optimism toward her profession that might seem unusual under the circumstances.

“This is what I do for my living, just like anybody else who has a job,” said Wash, who according to family stories has been singing since she was 2. “In any other job or occupation you have to be careful, or you get swallowed up. (Music) is just like any other business. It just happens to be a billion-and-billion-and-billion-dollar business.”