ART: In Amicus Monstrum, long-time gallery artists and friends, Scott C. and Nathan Stapley, will showcase paintings that tall tales of charming monsters and friendly mythological figures.

7 to 11 p.m. // Gallery 1988 (1173 Sutter St) // free

FILM: At An Evening with Roger Ebert & Friends, Ebert will be joined by filmmakers Philip Kaufman (The Right Stuff, Henry and June), Errol Morris (The Fog of War, The Thin Blue Line), Jason Reitman (Up in the Air, Juno) and Terry Zwigoff (Ghost World, Crumb) for a celebration of Ebert's long career, followed by a screening of his chosen film, Erick Zonca's uncompromising 2008 genre-buster Julia.

5:30 p.m. // Castro Theatre (429 Castro St) // $12-15

MUSIC: Mecury Cafe One-Year Anniversary and May Day Celebration will feature live music by Sour Mash Hug Band, Four Inch Pony, Janay Rose -- urban country western meets hobo folk with some pretty cute poetic twists in between.

7 to 10 p.m. // Mercury Café (201 Octavia St) // $5 musician donation