Joe Pratt of Source One Band Credit: Peter M. Hurley

We don’t often think of sidemen as comprising a “supergroup,” but there’s really no other way to describe Chicago’s Source One Band. Between them, bassist and bandleader Joe Pratt, lead guitarist Sir Walter Scott, keyboardist Stan Banks, and drummer Lewis “Big Lou” Powell have performed or recorded with a list of greats that starts with Koko Taylor, the Chi-Lites, the Jackson 5, Tyrone Davis, Otis Clay, Denise LaSalle, Johnnie Taylor, Artie “Blues Boy” White, Willie Clayton, and Latimore—and keeps going from there. These days, Source One’s featured vocalists are versatile deep-soul stylists New Orleans Beau and Joe Barr, who are equally adept at wrecking the house and at creating a feel of smoky intimacy when it comes time for lovemaking. But the band is as much of an attraction as the singers: Pratt, who formed the first Source One in the 1980s (when he was White’s bassist), sets the tone with his deep-pocket grooves and affable stage presence; Scott draws on an armamentarium of chordal and rhythmic colorations and expressive, melodically adventurous solo licks developed during five decades as one of Chicago’s first-call session men; Banks, a former Koko Taylor sideman nicknamed “Preacher Man,” adds a churchy emotional fervor; and Powell, who divides his time between his gigs with Source One and his tours with soul-blues legend Latimore, plays with a propulsive funkiness that’s never overwhelming. The overall feel is of a vintage revue—the band is dedicated and professional, yet loose enough to imbue the music with the kind of swaggering ebullience that feels like the epitome of hipness when the groove gets good and the solos lock in.   v