“[Insert Name of Famous Dead Person Here] Would Have Been 100 Years Old Today” is a common PR trick, like adding the word “festival” to the end of any event, and we usually don’t fall for it. You know what’s noteworthy? When someone actually lives to be 100. In the classical world, Elliot Carter is age 103 and still actively composing! Hence, the upcoming 2013 centennial for Benjamin Britten, who would have been 100, can’t possibly compete. (He died in 1976.) The New Century Chamber Orchestra, under the direction of Nadja Salerno-Sonnenberg, gets a head start on next year’s Britten banner-waving with his Simple Symphony, Les Illuminations, and some Bartók thrown in too, on Sunday, Sept. 23, at Osher Marin JCC. 200 N. San Pedro Road, San Rafael. 5pm. $29—$59. 415.392.4400.