Tonight's UCLA Live concert commemorates the 50th anniversary of the Ash Grove, the legendary folk-music club that defined '50s- and '60s-era LA music. Ash Grove's alumni are an impressive bunch, including Bob Dylan, Pete Seeger, June Carter, Joan Baez, Arlo Guthrie, and Kris Kristofferson. While many of these artists can't make it to this evening's festivities, the Royce Hall extravaganza breaks out some big names nonetheless: Taj Mahal, Michelle Shocked, Roland White, Ry Cooder, and some yet-to-be-announced surprise guests.