Surrounded by a gaggle of noisy architectural neighbors, the new Clyfford Still Museum in Denver makes itself heard by speaking softly but clearly. Instead of the thunderbolt lines of Daniel Libeskind's addition to the Denver Art Museum next door, the quirky massing of Gio Ponti's 1971 North Building for that museum across the street, or the grandiose Postmodernism of Michael Graves's Public Library a block away, Brad Cloepfil's two-story Still museum is a calm haven for viewing the work of the pioneering Abstract Expressionist who died in 1980.