Most of us Conspiracy Researchers will recall the case of Apollo 10 Astronauts : Tom Stafford, Gene Cernan and John Young discussing the “outer-spacey” music they head while on the far side of the moon. This music happened during the LOS (loss of signal) period that occurred while the communications between themselves and mission control were temporarily unavailable due to their position behind the moon. Gene Cernan is the first to hear the music (in the LM) and the transcripts shows that he radios John Young in the CSM to confirm he is hearing the same thing. John young then replies “Yea, I got it too…….and see who was outside?” Not only does JY confirm he hears it, but look at his following statement, “and see who is outside” ! Now who could be “outside” the space vessels?! More importantly John Young is inferring that there may be a connection between the “music” and “who is outside” of their crafts. After a few minutes of dialogue regarding the mission Gene Cernan brings up the topic again, “boy, that sure is strange music” in which John Young replies “ Were going to have to find out about that. Nobody will Believe us.”More at the link, where you can access Apollo 10 transcripts and experiences by other astronauts. Here is one possible explanation:
During their next orbit of the dark side the “music” RETURNS. Addressing Tom Stafford this time Gene Cernan asks “You hear music Tom? That crazy whistling?” In which Tom Stafford replies “I can hear it.” Gene replies “that’s really weird” and Tom replies “it is.” Further on Gene AGAIN brings up the subject by stating “Listen to eerie music”. They even continue random dialogue regarding the music and how eerie and weird it was, and that nobody is going to believe them.
There hasn't ever really been an "official" explanation of these sounds (described as whistling and buzz-saw sounds). But most scientists offer that it could be attributed to either radio interference in the lander or perhaps an artifact of the Sun's solar wind.
Since the most prominent example of this sound was when the Apollo 15 astronauts were on the far side of the Moon, it could be suggested that the Moon's gravity was gravitationally focusing the Sun's wind (a mix of high energy charged particles) onto the capsule. That interaction would created electromagnetic distortions, which could produce sounds inside the capsule.