With an internationally celebrated career exploring classical, jazz, and bluegrass, Edgar Meyer is a bassist who can play whatever and wherever he pleases, and lucky for us, the dude sits in on multiple gigs throughout the final week of Chamber Music Northwest’s top-notch summer festival. Tonight and tomorrow, in a setlist that stretches across 250 years, Meyer helps perform a contemporary work for strings that he created, as well as a composition from unequaled Baroque master J. S. Bach. After intermission, the brilliant Dover Quartet adds violist Paul Neubauer to their ranks to bring Brahms’ final string quintet to life. by Brian Horay