It’s Labor Day again, which means that the I Street Block Party around the  vicinity of Los Bagels and Wildwood Music is back at it again. And thank heavens for that because in these uncertain times, we could all use a little tradition to lean on. The tunes are free and kick off around noon. The lineup is as follows: Lizzy and the Moonbeams (noon to 1:30 p.m.), Citizen Funk (2:10-3:40 p.m.) and Timbata (4:10-6 p.m.). Go get it.