With his aggressive, love-me grin and oily good looks, Michael Feinstein comes across like the ultimate cocktail-lounge crooner, so the fresh phrasing that makes old standards shine like new is especially impressive; there isn't a cliched inflection to be heard in Feinstein's performance. At his best--when he's singing the best material--he's a sublime dramatic interpreter. The nagging flaw in Feinstein's art is that he's as good with junk as he is with the good stuff. He brings to the mediocre hackwork of songwriters like Johnny Mandel and Marilyn and Alan Bergman the same passionate incisiveness that informs selections by George and Ira Gershwin, Cole Porter, Irving Berlin, Jule Styne, Sammy Cahn, and Stephen Sondheim. It's a little like watching a great opera singer offer a recital of Mozart and Meyerbeer--the lack of differentiation leads one to question the performer's taste. Feinstein's consistency is impressive, but it makes me a little suspicious: maybe he's too good to be emotionally true. But then along come those sublime Gershwin songs--sung better than I've ever heard--and my doubts, if not swept away, are at least buried for the time being. And the guy's obvious love of what he's doing is irresistible. Tonight and Saturday, 8 PM, Sunday, 3 PM, Tuesday and Wednesday, 8 PM, Thursday, 2 and 8 PM, next Friday and Saturday, March 16 and 17, 8 PM, and next Sunday, March 18, 3 PM, Civic Theatre, 20 N. Wacker; 902-1500 or 346-0270.