Both trombone player Jeb Bishop and percussionist Tim Daisy have long résumés as collaborators and improvisers. Bishop's past is dotted by last names such as Brötzmann, Vandermark and Zerang, while Daisy has also worked with Vandermark, Fred Lonberg-Holm and Dave Rempis. But their debut disc together, the live duo session Old Shoulders, pushes past those associations, exploring extreme dynamics and twists on complicated themes. The majestic Regina Hexaphone opens the free show at 8 p.m. —Grayson Currin