If I'm in Jamaica, I'd like to hear reggae/dancehall...not blues...not alt rock...not bad covers of Southern rock...so...I guess it'd depend on the playlist...BUT
I think what we're discussing here is common courtesy. But someone always has to be the rude American tourist and keep the stereotype alive.
If I ever chose to play my music on the beach, I'd ask the people around me if they minded the volume. Same with smoking...no big deal...plenty of room for everyone...I can walk down the beach a bit.