Against the Institute of Contemporary Art's glass-wall harbor view backdrop, the Ditson Festival of Contemporary Music ended Sunday afternoon with Gil Rose, the festival's artistic director, conducting his own ensemble, the Boston Modern Orchestra Project. The program, on the surface, was mostly dedicated to a mainstream brand of new classical music not too crazy, not too dogmatic. But even this roster showed how varied and polyphonic the "contemporary" category has become.
In one way or another, every piece referred to musical history; the first half's trio of works made a particular point of it. The oldest, Harold Shapero's vigorously neoclassic 1948 Sinfonia in C minor, opened the concert in a slightly ragged but enthusiastic performance. Modeled after Haydn and Beethoven, the Sinfonia, with its jabbing offbeats and edgy orchestration, pulls off a neat historical slingshot, reaching back in time to hurl itself into the present.