True to their word, Community fans gathered at Rockefeller Center this afternoon to sing “O Christmas Troy” to NBC. So many black goatees! Evil flash mob! There’s also a super fun moment where it’s unclear if “Go Greendale, go Greendale, Go” is going to be like a full-on chant, or a one-time rallying cry, or what. Sigh. Comedy nerds are the best people to flash mob with.