(c) 2007 - 2011 West High Entertainment Unit Parents Association About the Entertainment Unit Jazz Ensemble Jazz ensemble is open only to upper classmen by audition from marching band. Membership in another instrumental music class (Wind Ensemble or Advanced Band) at West High School is a prerequisite. Selected instrumentation will include four to five trumpets, four trombones, five saxophones, one piano, one drum set, one guitar, and one bass. Admission is by permission of the Director. Attendance at al performances and rehearsals are required.