Those who are familiar with Uri Caine only as an avantist acoustic pianist, or Christian McBride as the neo-bop acoustic bassist of choice, will be blissfully surprised by The Philadelphia Experiment. Teamed with Ahmir Thompson, drummer for hip-hop titans The Roots, the band explores the depth and breadth of funky soul as it hasn't been heard in years. The freshness of their approach, and the many chances taken, breathe new life into a potentially stale musical form. Guest spots by guitarist Pat Martino, cellist Larry Gold and trumpeter John Swana boot several tracks to higher levels.

The opening track begins as sort of an odd-man-out, Caine's rippling electric piano setting a somber mood behind Martino's cool lines and Swana's '70s-Milesian tone. For a moment the tune sounds like an On The Corner outtake, but things open up and the funk swells overboard in good time. Funk is crowned king on "Grover," where McBride's electric bass is amped up with Mu-Tron "whoomps" a la Bootsy Collins, and Caine grooves like early Zawinul on the electric piano. On the opposite end of the musical spectrum is Elton John's "Philadelphia Freedom," a duo between Caine on acoustic piano and cellist Larry Gold that would sound out of place if it wasn't so letter-perfect. Other tracks include two from the repertoire of hometown fusion favorites Catalyst, Sun Ra's "Calling All Demons" (with Martino as the inarguable star of the show), and Marvin Gaye's "Trouble Man" as a feature for Swana's moody muted horn.

There are a couple of sound group improvisations included. "Lesson #4" is a trio jam that flaunts the band's taut interplay and soloing skills. Thompson is here, as always, zeroed right over the pocket. While the liner notes state that "The Miles Hit" is "the sonic equivalent of a Jackson Pollock painting," the track bubbles over with a fiercely organized basal groove that Pollock never quite let emerge. The bass/piano duo "(re)Moved" shows Caine in a more familiar mold, conjuring pinpoint melodic flurries over McBride's fleet, visceral acoustic churning.

The disc closes with two barn-burning solo spotlights. Grover Washington Jr.'s "Mr. Magic" is the last listed track, translated by Caine into a wondrously meditative acoustic piano study. The gospel inflections and ruminative bluesiness add up to one of Caine's best individual works yet. After a couple of minutes of respectful silence, we're treated to a multi-tracked bass rendition of Bill Withers' "Just The Two Of Us." After all, one can't expect McBride to just fade away without one of his trademark ventures into the soul canon, can one? A butt-rockin' thumb-slapped rhythm line supports the high-register fretless melody and handclaps. It's an ideal ending to a surprise-packed, highly successful experiment.