by Michael G. NastosChris Potter's quartet Underground should be looked upon as one of the many facets in the saxophonist's prismatic view of contemporary jazz. Certainly the band is oriented toward a progressive jazz image with the electric guitar work of the brilliant Adam Rogers and Craig Taborn's witty and pungent Fender Rhodes keyboard. Assumedly the concept of Underground harks somewhat to the fusion of Miles Davis, Herbie Hancock, and Chick Corea. But Potter's vision with this combo goes beyond those static and funkier values, entering a wilder, unabashed, and fierce aggression that cannot be corralled. In live performance at the storied Village Vanguard nightclub in Greenwich Village, you expect and receive long drawn-out compositions, extended solos especially from Potter, and new music tried out as audience experiments. "Train" is a long 16-minute trip, with mixed meters starting in 3/4 and going to 6/8, building momentum and leading to alternating beats of nine and seven and Potter's extended opening salvo solo. This is intense music -- sliced, diced, marinated, and flash-seared by Potter. "Arjuna" (not the Yusef Lateef composition) is a spectral sound analysis, lower key and illuminated, with a drum solo from Nate Smith, a Rhodes solo, choppy sax, and a workout from Potter and Rogers. Fond of interval leaps and overblown harmonic displacements, Potter's tenor is driven during "Viva Las Vilnius" over a quirky rhythmic idea meshed with a funky bottom end and Latin or ethnic inferences. The last two pieces of the set are decidedly settled, as Taborn's soulful electric piano on the sparse ballad "Zea" places the group in a calmer place and Potter plays delicate bass clarinet in an upper register atypical of its usual throaty sound. The finale, "Togo," is a version of the great melodic composition drummer Ed Blackwell brought to the repertoire of Old and New Dreams. It's very well rendered, with Potter sticking to bass clarinet, understating the melody with reverence and respect before Taborn goes crazy, stepping up the vibe into a funky mode while Potter switches to tenor and plays the calmer final chorus. For Potter's fans, this is a worthwhile addition to his growing discography. Considering Potter as a new music composer, this indicates how his music is changing and still flowering, and in a developmental stage. Evidently Potter and the audience were very pleased with the results, and perhaps a second volume of these sessions is in the can.