Babyface, Bjork, Me'shell Ndegeocello, and Nelle Hooper: Madonna's sixth studio album is packed with bigwigs, and Bedtime Stories is a product of a hodgepodge of different celebrity collaborations.

Madonna's previous album Erotica (possibly her most intense work to date) found her taking on a darker, unconventional style as a pop singer; it was a very ambitious project. But with the follow-up Bedtime Stories, she trades the all-consuming energy of Erotica for stylistic heterogeneity. The inclusion of collaborators with diverse musical backgrounds is surely an experimental move, just as ambitious as her move with Erotica.

Though flavored with contrasting styles of pop music, Bedtime Stories, if summed up, is Madonna's R&B album. Thanks to its main producer Dallas Austin -- who has produced albums for R&B acts like Janet Jackson, TLC, and Boyz II Men -- it has a definite R&B influence, though made subtle by Madonna's natural disco instincts.

The great thing about Bedtime Stories is that the star-studded guest appearances have made distinctive contributions on the album. Each of these artists have graced the tracks they are featured on with the personalities of their unique music styles. Like the markedly funky bass hooks on "I'd Rather Be Your Lover," which features Me'shell Ndegeocello on bass and vocals; the silky smooth love melodrama on "Forbidden Love" and "Take A Bow," which features Babyface in the songwriting and producing roles; and the spacey 90s psychedelic electro-pop glaze on the title song, which features Bjork as a co-writer and her chum Nelle Hooper as the producer.

Even though Bedtime Stories is an album of variegated dispositions, it lacks the depth and fire of Erotica, and is sometimes a bit too casual; it is a comparatively weaker effort. Still, it is a great pop album in itself. It shows the versatility of this "material girl" as a mature pop-artist who can dare to try out new musical experiments and come up with excellent results.