It used to be that rock was a simple, straightforward sound. It had a backbeat ("You can't lose it," as Chuck Berry reminded us) and was played mostly on guitars and drums. All you had to do was say the word, and everybody knew what you wanted to hear.

Not anymore. These days, rock draws upon all sorts of beats, from the nervous frenzy of thrash to the convoluted syncopations of hip-hop, and is played on every instrument imaginable -- including samplers and turntables, things most folks wouldn't even count as musical instruments.

Where once it meant something specific, now rock has become a generality, less an identifying label than an all-encompassing aesthetic. But that's all for the better, because if rock remained so narrowly defined, it's doubtful we would ever hear albums as alluring and adventurous as Jamiroquai's "Synkronized" (Work 69973) or Cibo Matto's "Stereotype A" (Warner Bros. 47345, both arriving in stores today).

Neither fits traditional notions of what a rock album should sound like. "Stereotype A" draws on everything from hip-hop and funk to hard rock and bossa nova, while "Synkronized" takes as its touchstones everything from acid jazz to '70s Stevie Wonder to "Off the Wall"-era Michael Jackson.

Yet both albums speak to basic rock and roll impulses -- the need to express a specific cultural identity and to have fun while doing so.

For Cibo Matto, the issue of identity is particularly nettlesome. Formed by Miho Hatori and Yuka Honda, two Japanese expatriates living in New York, the group made a stunning debut in 1996 with the sinuously melodic "Viva! La Woman."

But even though the album garnered the group a lot of press, Hatori and Honda found themselves forever portrayed as quirky and cute, a pair of pop Hello Kitties who wrote funny songs about food. Consider "Stereotype A" a corrective to that particular Asian stereotype. As Hatori puts it in "Sci-Fi Wasabi," a gently mocking send-up of how Cibo Matto has been portrayed, "Your vision of stupidity's made out of vanity."

The most important part of Cibo Matto's identity isn't cultural, it's musical. Like the Beastie Boys and Talking Heads before them, the members of Cibo Matto -- which, in addition to Hatori and Honda, include Sean Lennon and Timo Ellis -- are master assimilators, rummaging through a jumble of pop styles to assemble a wholly original sound.

"Lint of Love" is a case in point. At first glance, the song seems just another soul-obsessed dance track, what with its chattering clavinet and jangly, James Brown rhythm guitar. But as the track unfolds, its sonic universe expands in unexpected directions, detouring into cool, keyboard-and-trombone intermezzos and jaunty, rap-spiked breakdowns.

By the time the band works its way to the semi-metal guitar riff at end of the arrangement, it's as if we've been around the world and back again. And yet, the music's flow is so sure and steady, the central groove doesn't let up for a second.

(It should also be added that the lyric, which uses laundry as a metaphor for love, is pure -- if unexpected -- genius.)

Even when the group makes an obvious pass at a specific style -- drawing on rap for "Sci-Fi Wasabi" or bossa nova for "Flowers" -- what it ends up with is utterly individual and impossible to pigeonhole. In fact, the album's best tracks, like the sinuous, funky "Spoon" or the dreamy, lightly Latin "Moonchild," are, like Cibo Matto itself, utterly unique, owing their charm not to any specific sources but to the sheer singularity of the group's sound.

There's nothing quite so original about the sound Jamiroquai gets for "Synkronized." Indeed, the group's point of reference is so obvious at points that some songs seem out to prove that imitation is the sincerest form of flattery.

"Canned Heat," for instance, seems a compendium of early-'80s Michael Jackson moves, from the falsetto of the opening refrain -- "You know this boogie is for real" -- to the string section exclamations that punctuate the arrangement. Then there's the "Shaft"-style bass riff that anchors "Soul Education," or the jazzy, Stevie Wonder-ish twist given the chorus to "Butterfly." It doesn't take too many hearings to get a sense of what albums Jamiroquai's J. Kay has been playing lately.

Yet to suggest that "Synkronized" is merely an exercise in retro soul would be a serious misreading of the album. Because Jamiroquai's vision of the past says much more about contemporary taste than '70s style.

Despite the album's fondness for vintage sweeteners like strings, brass and percussion, Jamiroquai's sense of sound is totally contemporary.

"Black Capricorn Day," for instance, may salt its driving funk groove with sassy horn interjections, but it treats them like something a DJ might have dropped into the mix -- at points stuttering the horn line like a record on a turntable. And "Planet Home" feels like straight, bass-driven funk but draws most of its sounds, from ghostly ambient harmonies to bone-shaking synth bass, from the vocabulary of techno.

In effect, this retro/nuevo approach allows Kay to have the best of both worlds. As a songwriter, he's able to mine the conventions of classic '70s soul for harmonic sophistication and melodic content, qualities infrequently found in techno.

At the same time, by making the most of today's studio technology, he's able to concoct a sound that's not only totally modern, but which couldn't have existed even a couple of years ago. Hence the aural extravaganza that is "Supersonic," in which didgeridoo and dobro drone against electronic percussion and a squiggling synth bass, all of which builds to an hallucinogenic mid-song samba break. Play this through headphones, and you'll have no trouble understanding what Kay means when he sings, elsewhere on the album, about having "canned heat in my ears."

Admittedly, "Synkronized" offers more in the way of ear candy than in provocative lyrics, but that's kind of the point. Jamiroquai is essentially Dionysian music, designed to appeal to the hedonist within. And frankly, "give in" is as profound a message as this band needs.

New releases

Cibo Matto

"Sterotype A" (Warner Bros. 47345) Sun score: ***

Jamiroquai

"Synkronized (Work 69973)

Sun score: *** 1/2

Pub Date: 6/08/99