Like the wild mushrooms that fungus enthusiast Robert Rich turns into gourmet dishes, the pieces on Soma seem to emanate directly from the ground, without belonging to any species hitherto defined. New Age? Nah. Ambient? Not exactly. Fungoid tribal trance? Maybe. Rich, the drone provocateur who invented the "sleep concert" in the early '80s, and Roach, proto-ambient pioneer whose Dreamtime Return remains a classic of organic New Age, distill a potent nectar of heartbeat-paced percussion--including rain sticks, clay water pots, kalimbas, and sequenced drums--and reverberant flutes, didgeridoos, and canyon-sized synthesizers. More rhythmically active than either the Roach-Vidna Obmana duet Well of Souls or early Roach electronica like Traveller, Soma--named for the Vedic potion said to deliver the drinker to God--is a Southwest vision quest that suggests Terence McKenna's psilocybin-mushroom theories: a connection to the very soul of the earth through ethno-botanical ingestion. Bottoms up.While STRATA, the first collaboration between Steve Roach and Robert Rich, sought to peel away the substratum layers of the inner consciousness, SOMA attempts to reconcile those emotions with the outer world through a wondrous, gripping corpus of sound. Here, Roach and Rich perform a stunning series of lively, aural mosaics that are like musical puzzle boxes with hundreds of oddly colored pieces. It is as if they tore up the veneer of the desert itself and constructed these sounds out of the earth's very natural fiber. Like the best free jazz improvisers, Roach and Rich intuitively communicate their separate identities into one collective whole. Another brilliant collaboration from two higly prolific and accomplished artists.