The musical numbers in "De-Lovely" come close to fulfilling the promise of the film's title, but then they are interrupted by director Irwin Winkler and his stars. Bad idea.

The real problem here, though, is that this musical biography of Cole Porter tells its story through conventional means, with leaden dialogue and few, if any, insights. The film is just over two hours, but it feels considerably longer.

The film doesn't shy away from discussing Porter's homosexual relations, with a strong gay undercurrent running through the entire movie. But, being a PG-13 rated film, it never gets too salacious.

"De-Lovely" begins with Gabe (Jonathan Pryce), a musical producer, apparently trying to mount a stage show based on Porter's life. He's even gotten the aging composer/songwriter (Kevin Kline, under heavy makeup) involved.

The bulk of the film is told in a series of flashbacks, with the emphasis on Cole's relationship with Linda Lee (Ashley Judd), a wealthy divorce who's tolerant of his extracurricular and extramarital activities. She's also supportive of his career, which begins taking off when he's discovered by Irving Berlin. Suddenly, he finds himself the toast of Broadway. However, his adulterous liaisons with other men continue, even when serious health issues surface for both of them.

Jay Cocks' screenplay is all about artifice, and there's not much depth with either of the main characters. Depending on your point of view, this treatment is either too edgy or not nearly edgy enough. And Winkler's flat-footed direction certainly doesn't help.

On the plus side, there are terrific renditions of many of Porter's songs, performed by Robbie Williams, Diana Krall, Elvis Costello, Sheryl Crow and Natalie Cole. All are splendid, but far too brief. (Though Alanis Morissette adopts a weird melodramatic quaver for her version of "Let's Do It, Let's Fall in Love.")

Even Kline and Judd do their share of crooning (oddly, there are no cutaways from them, as there are for the singers recruited for this film), but musical-theater veteran Pryce stays nearly silent, which is an unfortunate misstep, since he has a much better voice than either of the stars.

"De-Lovely" is rated PG-13 for vulgarity (innuendo-laced song lyrics), scattered use of profanity, some brief sexual contact, glimpses of nude artwork, and references to drug use (painkillers). Running time: 125 minutes.