Rap music is in a serious transitional period. The strides made in instrumental hip-hop over the past few years have far outstripped the gains created by the MCs, the most famous of which are coasting easily on well- established clichés. To paraphrase Ralph Waldo Emerson (forgive the pretension, and also my theft of this analogy from my good friend Samir), "You can't have great rappers without great audiences." As long as the nation continues to line the pockets of those pontificating from one side of the "playa" debate, we can expect the lyrical assault to remain forever mediocre. Maybe we've come to expect too much-- after all, nobody requires rock lyricists to continually evolve. But rap comes from the hip-hop cultural tradition, where you either innovate or die, and few of the microphone styles circulating today deserve to survive natural selection.

Attempting to change that is the Quannum crew, a collective of Bay Area hip-hop heads who met and began collaborating in the '80s in and around the campus of UC Davis. DJ Shadow is the band's key to success, and also the only straight producer of the bunch-- the rest are comprised primarily of the MCs from Latyrx and Blackalicious, in addition to vocalist Joya Velarde. The Jurassic 5, though from Los Angeles, have a close relationship to this crew, forged with a shared aesthetic and high- minded ideals about the next phase in hip-hop music. Quannum's Spectrum functions as a sort of introduction to the collective-- a label sampler of sorts for their new Quannum imprint.

As Shadow's already well established outside of the group, his contributions here are understated. He created the music for four of the tracks, but as anyone who has heard the Latyrx album can attest, Shadow likes to keep his backing tracks simple, tight, unobtrusive and easy to rap over. He reins in the high- drama and sampler virtuosity of his solo work, but the tunes are uniformly funky and serviceable.

Those familiar with the Jurassic 5's quickly acknowledged classic EP will love the first tune here, a freewheeling jam with Jurassic and all the Quannum MCs based on the children's song "Concentration." Despite production by Lyrics Born of Latyrx, it maintains that trademark Jurrasic 5 schoolyard spirit. But if "Concentration" is the best song here, it's by no means the only great one.

The rest of Spectrum's tracks intertwine sampled '80s R&B; riffs (Verlarde's "People Like Me"), updated old- skool lyrical trade- offs ("The Extravaganza" with the Quannum MCs and Souls of Mischief), and deep semantic intelligence. A true all- star game of West Coast underground hip-hop, Spectrum is supremely satisfying when you think about where rap is at the moment, and only disappoints when you think about where it could be.

-Mark Richard-San