By Tobias Carroll Many, many years ago I was at a basement show in New Jersey. Well, that’s not entirely accurate — at the time, I was with friends talking in the back yard while a basement show happened in the basement.The guy who’d organized things wandered over to us and ushered us downstairs, arguing that it would be rude not to watch the band currently playing. It wasn’t the first time I’d had cause to think about the etiquette of watching live music, and it wouldn’t be the last. Some of those same issues came up while watching a recent video posted on Instagram by Adrianne Lenker, known …