Tribeca Film Festival: What to do on Tuesday

Master Class:

The Sound of the Coens

The Coen brothers are cinematic geniuses in every sense, so you could probably spend hours doing nothing but discussing the soundscapes of their movies. This free discussion, with their frequent composer Carter Burwell and sound mixer Skip Lievsay, is a must-attend. Today at 2:30 p.m., SVA Theatre, 333 W. 23rd St.'The Survivalist'

This spare post-apocalyptic flick is fast becoming one of the discoveries of the fest, praised for its uncompromising portrait of a man, a mother and a daughter struggling to survive amid an unforgiving landscape. Today at 9 p.m., Regal Battery Park Stadium, 102 North End Ave.'(T)error'

This chilling documentary, in which filmmakers follow an FBI informant and the subject he's targeting, evokes important and complicated moral questions about the ways we pursue our national security. Today at 9:15 p.m., Bow Tie Chelsea, 260 W. 23rd St.'Grandma'

Look, Lily Tomlin is a national treasure. So why wouldn't you want to try out this comedy in which she plays a grandma on a road trip with her granddaughter? Today at 6:30 p.m., Regal Battery Park Stadium, 102 North End Ave.