Actually, this mystery was solved long ago. From Chapter 13 of Carrying The Fire by Michael Collins: "There is a strange noise in my headset now, an eerie woo-woo sound. Had I not been warned about it, it would have scared the hell out of me. Stafford's Apollo 10 crew had first heard it, during their practice rendezvous around the Moon. Alone on the back side, they were more than a little surprised to hear a noise that John Young in the Command Module and Stafford in the LM each denied making. They gingerly mentioned it in their debriefing sessions, but fortunately the radio technicians (rather than the UFO fans) had a ready explanation for it: it was interference between the LM's and Command Module's VHF radios. We heard it yesterday when we turned our VHF radios on after separating the two vehicles, and Neil said that it 'sounds like wind whipping around the trees.' It stopped as soon as the LM got on the ground, and started up again just a short time ago. A strange noise in a strange place." Page 420 (in my edition of the book, anyway).
This reminds me of the stories about Friendship 7; the "fireflies" that John Glenn saw turned out to have a logical explanation, but UFO conspiracy theorists choose to ignore it. Aliens on the far side of the Moon are more interesting than VHF interference.
"My feet they finally took root in the Earth, but I got me a nice little place in the stars, and I swear I found the key to the universe in the engine of an old parked car..."
Let me tell you a little story laurel... Once upon a time a bloke brought this "Apollo 10 music" thing up on another board and at the time I had never heard of it so, being intrigued myself, I did a google search and after a while was directed to a post of yours on the BAUT you made a while back addressing this very topic. Armed with this info I returned to that board and posted the explanation and link to your post and as a result ended up saving that bloke's soul from the dark side and learned something new in the process.
I tipped my hat to you then and do so again, this time "in person." Well done.