Like a number of progressive chamber music ensembles, the Vermeer Quartet often balances its programs with established 20th-century classics. This season, in its subscription series for Performing Arts Chicago, however, the estimable foursome has become even more adventurous: it's presenting two local premieres of works by living composers. Part of the credit probably goes to violinist Mathias Tacke, who was a member of an avant-garde collective in Germany before joining the quartet last season, Tacke can produce a more somber tone than his predecessor and has a better grasp of contemporary string literature, and his zeal seems to have rubbed off on his colleagues; last season, for the first time in a long while, they shook off the tasteful reticence that marked many of their past performances of modern pieces. All of this bodes well for Lowell Liebermann's brand-new work for quartet and mezzo-soprano (to be premiered early next year) and for Twelve Microludes by Gyorgy Kurtag, which tops the bill at this week's concert. Kurtag, who was born in Romania but emigrated to Budapest early in his career, was influenced first by Bartok and Kodaly, later by Webern and Berg. Twelve Microludes, written in 1977 and only ten minutes long, is wickedly Webernian, consisting of a dozen miniatures that are as fleeting and enigmatic as haiku. Rounding out the bill are Dvorak's Quartet no. 9 and the lyrical and melancholy Quartet no. 2 by Tchaikovsky. Sunday, 3 PM, concert hall, DePaul University, 800 W. Belden; 242-6237.