Barry Gibb's superstar trio, the Bee Gees, may have been in decline by 1980, but the leisure-suited disco heartthrob sure did something to Barbra Streisand. She'd had hit duets before, with Neil Diamond and Donna Summer, but none of them connected to her Broadway voice as Gibb did with the smoldering pop of "Guilty" or the pointed ballads "Woman in Love" and "What Kind of Fool." All three hit the Top 10, the Streisand-Gibb duet album "Guilty" sold more than 5 million copies, and the title track won a Grammy.

It's the 25th anniversary of that album, which doesn't have quite the same cultural significance as, say, the 25th anniversary of the Clash's "London Calling," but it's enough for Gibb, 59, and Streisand, 63, to reunite and search for the old pop magic. On Streisand's new "Guilty Pleasures," the leonine disco hero and the blue-eyed diva snuggle once again on the album cover -- only they're dressed in black, not "Saturday Night Fever" white.

Three Gibbs write most of the songs, as the Bee Gees did on "Guilty" -- only this time it's Barry and his two sons, Ashley and Stephen. And Streisand again sings a soft, catchy collection of ballads and upbeat pop -- only her voice doesn't quite ignite with the material the way it did on "Guilty."

Streisand's singing is impeccable, as usual; she's the perfect adult-contemporary balladeer, and she shows her mastery of the craft on the gently waltzing "Come Tomorrow" (a duet with Gibb), the shimmering love song "Golden Dawn" and the tearjerker "(Our Love) Don't Throw It All Away."

Aretha Franklin or Etta James might have belted the latter with outrage and self-righteousness, but Streisand bobs passively over the lilting backup singers, as if staring helplessly out a bedroom window. It doesn't help that the Gibbs rely on stilted lyrics -- "Your flame is burning bright" (from "Stranger in a Strange Land"), "You and I can change the world, if we just try" ("Hideaway"), "There's something about that way you smile, every touch leaves me helpless" ("It's Up to You") -- which is like watching a great actress chained to a mediocre script.

Neither Gibb's production (with John Merchant) nor his two duets ever get in the way of the star attraction. The background music is almost completely subdued, with '80s-style synths and drum machines opening the album and shimmering chimes buttressing almost every ballad, particularly the over-the-top "Without Your Love." The lively exceptions are "All the Children," which has a forceful, "Evita"-like quality, and "Night of My Life," an upbeat disco track that Gibb seems to have retrieved from the '70s. Streisand sounds like she's having fun, something we haven't heard from her in years.

But even "Stranger in a Strange Land," the closest thing on "Guilty Pleasures" to capturing Streisand's well-known liberal political views, doesn't have the hunger of the original "Guilty" album. It begins with a timely reference -- "You may be someone else's sweetheart, fighting someone else's war" -- but it turns into a conventional you're-away-and-I-miss-you ballad.

Barry Gibb and Barbra Streisand snuggle once again on the album cover of "Guilty Pleasures," released on the 25th anniversary of "Guilty."