The draw this afternoon: the American premiere of Phoenix, a four-hand-piano concerto by the Turkish composer Fazil Say, himself a keyboardist of technical polish and vivid pictorial imagination. The soloists on this occasion, as at the world premiere in Munich earlier this year, are the Dutch duo pianists Lucas and Arthur Jussen, camera-ready young brothers (not twins) on the cusp of what promises to be a major career. After intermission, it’s on to the sublimity of the Brahms German Requiem. Another red-letter Tanglewood date this weekend: on Saturday evening, July 16, Andris Nelsons leads Mozart’s Don Giovanni in concert. (Hooray! No concept!) Within the mostly American cast, listen for Will Liverman, latest winner of the Metropolitan Opera’s Beverly Sills Award, as Leporello, who keeps score of his master’s sexual conquests. And on Sunday evening, July 17, the pianist Stephen Drury lets loose with The People United Will Never Be Defeated!, Frederic Rzewski’s colossal 20th-century bookend to Beethoven’s Diabelli Variations. —Matthew Gurewitsch