I believe this nonsense about astronauts hearing celestial music behind the Moon is just another part of the side-issue disinformation script that was written by NASA before the Apollo flights took place.

AS10-34-5091 Official NASA Apollo 10 photo reveals small model Lunar Lander supported by a person's hands above.
This below photo has only very slowly been brightened to show what is hidden in the background.

[link to i230.photobucket.com]

Heres the original photo location if you want to check and slowly brighten it yourself.
[link to www.apolloarchive.com]