The impact of summer movies is loud. "Men in Black," "My Best Friend's Wedding" and "Batman and Robin" draw millions into the theaters. But not all their stars are on the screen: The rap and R&B-based soundtrack to "Men in Black" was the No. 1 album in the country for two weeks this summer and has just been certified double platinum (2 million sold). "Batman and Robin's" alternative rock disc and the grittier funk and rap of Tim Robbins' "Nothing to Lose" have both broken the Top 20, while newer discs such as "Spawn" (which pairs punk and metal with techno and rap for a raw, rageful sound) and the hip-hop "Def Jam's How to Be a Player" are climbing fast. For an increasing number of young artists, a song on such a soundtrack can be the key to platinum dreams.

"Men in Black" is a perfect example. Will Smith's bouncy title track has certainly helped make this recording a hit. But the listeners who are keeping that sound-track high on top of the Billboard charts aren't just hearing Smith's smooth rap. As they play the disc, they're also being exposed to such contemporary R&B acts as the slick Ginuwine, hip-hop Nas, and sassy, sultry Alicia Keys. These lesser-known performers get to piggyback on Smith's fame, and on the success of the movie.How big a career boost can a new act hope for? Consider the case of Celine Dion. The French-Canadian singer and her smooth multi-octave ballads seem to be everywhere these days. But although she had sold enough to rate a gold record (500,000 copies) with her first English-language release in 1990, she really jump-started her career with a soundtrack - 1991's "Beauty and the Beast" pushed her sales up to platinum (1 million). Another soundtrack spot two years later, on "Sleepless in Seattle," bumped her sales to triple platinum. Her most recent album, "Falling into You" which features the single "Because You Loved Me" from the film "Up Close and Personal" has sold more than 23 million copies worldwide, according to Glen Brunman, executive vice president of Sony Music Soundtrax. "She's done three songs for movies, the only three she has ever done for movies, and clearly she's gained tremendously," says Brunman.

That kind of lift is exactly what record labels are aiming for these days when they put together sound-tracks. Label execs hope moviegoers will be intrigued by what they hear behind the credits, and then buy the soundtrack. When they get their souvenir home they'll hear that song - and all the others on the disc.

"It's a calling card," says Sire Records producer Andy Paley. The former Bostonian has worked on soundtracks for "Dick Tracy," "Shag," and most recently "Star Maps" (which mixes Latino rock, ska and pop). He points out how a young country artist, Lila McCann, went from recording a song for the soundtrack to last spring's "Traveller" to success with her debut CD this summer. Her first solo effort, "Lila," has shot up the Billboard charts as a "heatseeker," which means it's a record to watch. "The soundtrack introduced radio to who she was," says Paley.

"With a new artist, our marketing budget is somewhat limited," explains Darren Higman, vice president of Atlantic Soundtracks and VP/general manager of Big Beat Records. His label is responsible for the "187" soundtrack, a disc that features hip-hop by Method Man from the hugely popular rap group Wu-Tang Clan, but also showcases several lesser-known techno-artists, such as Jalal and DJ Shadow. "It's a way of separating a new artist from the pack," he says.

"It's not exactly rocket science," says Michael Mauldin, executive vice president of the black-music division of Columbia Records and senior vice president of the Columbia Record Group.