Conductor will also drop his hands between movements, so you can't always go by that. OP should have paid attention to what songs were being played, but I wouldn't be too harsh on them. "Slowly" realized is key though, I at least would've clapped once to check if anyone else clapped with me. As one of the players I'd have found it hilarious though.

What's up

it actually happens a lot at band concerts. most of the audience doesn't know how long the music is and where the rest measures are.

If you loved the song so much, you would know how it goes. Obviously you didn't know the song, so OP why were you at a concert of a music group whom songs you don't know?

*clap*… *clap*… *BOOOOOOOOOOOOOO*

dude that's like the worst concert ever than.. cuz ev1 is cheering throughout like every good concert! you should find a more popular band to go see

happens to the best of us

wait till the conductor puts his arms down asshole.

that's because your a niger go die

Lol. Awkward