Is music playing in the background of runs allowed? My duo and I wanna know if we can run with music for some morale lol

The rules do not state if dying during a co-op run is permitted, which if it is, then the meta could just be that it's a solo run with a dead person just being there

Are you able to use Discord or some other application to voice chat during a co-op run instead of using the in-game chat? Idk if distance chatting is going to be useful or not