I was waiting to be seated at Ohana and caught wishes from the beach at the Polynesian in March. There is plenty of space to sit or grab a hammock. I believe the music is piped into the pool area because you can hear it coming from the resort as well as across the lagoon.
I had seen Wishes from inside the MK two nights before so it was good to see the fireworks without the music. By that time, I was hearing it in my head anyway. Had I been seated by the window in Ohana, I'm sure the view would have ben just as good.