We had a MK view room at the CR from May 28 - June 2.
We watched Wishes from the balcony every single night. Of the 5 nights, 2 nights I could hear some of the music from the park (in between the booms). The other 3 nights, we didn't hear any music at all.
Channel 20 no longer carries the soundtrack (you can of course buy the Wishes CD and play it while you watch - it's just a matter of timing - make sure to start the CD as the Castle turns dark blue/purple and the stars appear on it).