In a departure from its usual fare, the Potomac River Jazz Club provided several hundred delighted listeners and dancers at the Twin Bridges Marriott Saturday night with a lively session of mainstream swing cum New York-style Dixieland by a group of professionals that calls itself the Split Apple Jazz Band. Working from charts, but by no means slavishly following them, the eight-man unit acquitted itself imaginatively in solo and constructed spirited ensembles that were tight with tension yet loose enough for individuality. One connotation, perhaps inadvertent, of the New York band's appellation was the balance of number and quality between the front line and the rhythm section, the latter's power calling to mind--and to feet--the Basie engine; the former evoking the horn sections of the better "bands within a band" of yesteryear, such as Bob Crosby's Bobcats.

Leader Randy Reinhart's exuberant and driving cornet employed Bixian rips on flag wavers and gave expression to pensive reflection on ballads. Veteran tenor saxophonist Nick Sassone's dry tone and rolling melodic line were tied to an innate sense of swing and the assertively gruff trombone of Pete Ballance was an effective contrast to the clear-toned clarinet of Bill Kroll. Guitarist Dawes Thompson's gravel-pit vocal on Jelly Roll Morton's "Sweet Substitute," a quote from "Salt Peanuts" by drummer Ed Metz Jr., the alternating string bass and tuba of Brian Nalepka and the rococo flights of pianist Ed Metz Sr. pointed up the versatility of a rhythm section not content to merely watch the clock.