Like nearly every modern-day pop genre, it is so splintered that each CD or tape should be sold with a pair of tweezers. There are aggressive men and assertive, spitfiring women. There are video-fueled novelty hits, unimaginative remakes of time-honored standards, and a dismaying number of cookie-cutter acts who unashamedly exploit whatever trend is in vogue. There are cocky loudmouths and flaky singer-songwriters — and, on the sidelines, a bench full of veterans trying to elbow their way back onto a very crowded playing field.

Rock? Yes. Country? No question. But now that scenario also applies to R&B. Ever since disco and funk boogied onto the scene in the ’70s, black music has developed more branches than the oldest musical tree; even rap has devolved into at least a half dozen offshoots. Soundtrack albums showcasing the many faces of R&B are released on a seemingly weekly basis, but few have matched the scope of Space Jam. In the same way 1992’s Singles soundtrack let mainstream rock fans sample some flannel shirts, Space Jam, the companion album to the Michael Jordan-versus-Bugs movie, is an entry point for anyone who hasn’t kept up with black music in the ’90s. It’s a Whitman’s Sampler of modern R&B.

Curious to explore the pumped-up, party-hearty groove of the Miami Bass sound? Crank up the Quad City DJ’s’ ”Space Jam,” a shameless Xerox of their irresistible summer smash ”C’mon N’ Ride It (The Train).” Eager for the quiet-storm ballads that routinely top current pop and R&B charts? Punch up the slurpy croonings of R. Kelly, All-4-One, and Monica. (Kelly contributes ”I Believe I Can Fly,” whose go-for-it lyrics and florid orchestration seem to have been written with a future Disney musical in mind.) Want to bypass gangsta in favor of less visceral, positive-minded rap? Turn to Coolio’s bubbly ”The Winner” and Salt ‘N’ Pepa’s cute, though inconsequential, remake of Diana Ross’ zingy ”Upside Down.” Another unnecessary cover — Seal’s note-for-note facsimile of Steve Miller’s ”Fly Like an Eagle” — is a showcase for the sonically perfect, pure-of-spirit modern soul Seal embodies.

Several old-school styles, updated by newcomers, also step onto the Space Jam court. ”I’ve Found My Smile Again” continues D’Angelo’s quest to revive the sheets-music mood of Marvin Gaye’s lubricated ’70s work. Disco is alive and well in Robin S.’ pleasantly formulaic ”Givin’ U All That I’ve Got.” Leaving no demographic untouched, the record crams in a few novelties (”Buggin,”’ a rap by Bugs Bunny) aimed squarely at preteens.

Such a jumble of tempos and moods works fine on urban-contemporary radio, which can segue from a Janet Jackson oldie to a manic Busta Rhymes rave-up and make the transition seem effortless. Space Jam, though, is too diverse for its own good. In particular, the preponderance of smooth-groove ballads during its second half dips the energy level dangerously low. (And if this album were a basketball game, a referee would have yelled ”Foul!” halfway through the Spin Doctors’ clubfooted version of ”That’s the Way I Like It.”) In a larger sense, the record sends out mixed signals about the future of R&B. The music is smoother and more polished than ever, but guiding lights like Kelly and D’Angelo still seem like talented middleweights, not genuine innovators.

At the very least, Space Jam shows one thing about R&B that has, thankfully, not changed: It’s still the most flesh-obsessed style of pop. When Quad City DJ’s’ JeLana LaFleur chants, ”Wave your hands in the air if you feel fine/ We’re gonna take it into overtime,” on ”Space Jam,” she’s talking about a very different kind of pickup game. And a full-court game becomes all-out warfare on ”Hit ‘Em High,” a hip-hop-hooray throw-down that pits LL Cool J against his harder, marble-mouthed successors — Coolio, Rhymes, Cypress Hill’s B-Real, and Wu-Tang Clan’s Method Man. Thanks to those two songs, you may never think of basketball in the same way. Maybe we’re witnessing the birth of yet another subgenre: R&B-ball. B-