For such a convoluted, self-referential art form, hip-hop constantly -- and unfairly -- measures itself in rigid, linear terms. Your school is either old or new, your ethos either stratospheric pop or subterranean underground, your bank account padded by zeroes or nothing but zero. Only an elite few hip-hop artists -- Native Tongues, the Roots, PE, Eminem -- have achieved a viable gray area similar to the one alt-rock carved out for rock 'n' roll in the '90s. But there's hope -- just ask alt-rappers like Aesop Rock, Atmosphere, and Boston MC/DJ/producer Edan. The 26-year-old triple threat has aired a couple of well-received mix tapes over the years as well as his debut LP Primative Plus, but Beauty presents a fully-fledged, densely-packed, psychedelic vision. The album doesn't break new ground -- it includes that well-worn trope, a time line/roll call of MCs (though Edan's all-stars are more obscure than others') as well as the admission that "Prince Paul already used this loop" to kick off a track redolent of Justin Warfield's shroomed-out b-boyisms. Instead Beauty builds its own hazy, kaleidescopic world from time-tested building blocks, where overmiked reverb and Pink Floyd samples rock side by side with snapping boom bap and Mr. Lif cameos. Solid gold? Not really, but with Edan, the gray area is good enough.