The Undead Jazz Fest is back to remind you that jazz is more than stuffy clubs, drink minimums and your worn-out copy of A Love Supreme. For four days BOOM Collective and Search & Restore are bringing 50 of the best artists from the new jazz and improvised music community to 11 venues, including the Bell House, Littlefield, and Public Assembly. Tonight at the Bell House, following Celebrate Brooklyn’s free Roy Hargrove show, is a night of round robin duets among 16 musicians including Elliot Sharp and Brian Chase (of the Yeah Yeah Yeahs!). For all shows, visit the Undead site.