Bay Area collectors reach critical mass

Trying to find a common denominator in the current show at Pier 24the massive photography foundation opened by the collector Andy Pilara on the San Francisco waterfrontis a brain game of the highest order. One gallery is filled with the modern-gothic images of Ralph Eugene Meatyard. Another has psychedelic colours and a music theme, with portraits of Bob Dylan, Janis Joplin and Aretha Franklin alongside visual riffs by John Baldessari and Christian Marclay.Although previous shows have had loose