After closing last year’s season with a magnificent presentation of the Monteverdi Vespers—one of the Ithaca community’s best classical musical events in years—the early music ensemble NYS Baroque, in its 27th season, will concentrate on more intimate music with small and unusual ensembles. Their opening concert, called French Café and featuring just four performers, takes place this Saturday, Sept. 26, at 7:30 p.m. in Ithaca’s Unitarian Church.