Chamber Music San Francisco didn’t have to go far to bring half of the Assad Brothers in for aconcert: Sergio is on the faculty of the San Francisco Conservatory of Music. But since Odair has to fly in from Brussels for the concert, you should catch them at Herbst Theatre on Tuesday, Feb. 19. Scott Cmiel has written "they are the preeminent classical guitar duo of the last 40 years, having set the standard for technical excellence, sensitive musicianship, and innovative repertoire choices and opportunities to see them together have been dwindling over the past few years."