To call Milwaukee's Peter Mulvey an acoustic singer-songwriter and guitarist just doesn't cover it. Mulvey, says the Washington Post, "makes music for grown-ups." There may not be another songwriter around who can draw a crowd into a really complex lyric as effectively as Mulvey does. His new album is called "The Knuckleball Suite"--because, Mulvey says, " A knuckleball leaves a pitcher's fingertips, and what happens next is anybody's guess. Its path is unpredictable; it is a hidebound enigma." Nothing here (or anywhere in Mulvey's output) is what it seems, and Mulvey stands at the center of this eclectic flurry, tossing things straight to you (right?), alternately poker-faced or grinning. He is joking. He is impassioned. He is bemusedly detached. He has no idea where this is headed. He means every single word.