Riley wrote In C in 1964 and effectively handed modern music a new operating system. A 90th birthday concert at a public library is exactly the kind of low-barrier, high-ceiling programming the Main Branch does well — expect pianists working through Riley's catalog in a room that is, acoustically speaking, fine but not precious. That's appropriate. His music was never meant to require a velvet rope.

Practical note: the Main Library's Larkin Street entrance is your cleanest approach from BART. The Civic Center garage on McAllister fills fast on weekday evenings; street parking on Grove is easier than it looks. Arrive ten minutes early — free events in that first-floor performance space fill to standing on less than this.

If you have two hours: catch the full performance, then walk one block to Zuni or two blocks to anything on Hayes. The neighborhood earns the detour.