it might have been major Tom ,

misleading title, not ONE of the astronauts was freaking out. In fact, they seemed actually rather calm and composed.

I am sure there is a perfectly plausible explanation for the sounds which this tv show deliberately obscures.
Also, the soundquality of the "space-music" somehow is on a completely different level than the rest of the transmission, which makes me suspect that we are not hearing the original sounds, but rather sound effects added by the sound engineers of the tv show.

It would have been Kraftwerk bouncing back from a blackhole

#5 rather than watching more of this questionable infotainment I went straight to the source.
Turns out the transcrips and recordings are publicly available since 1973 and didn't "emerge 4 decades later" (that's when NASA uploaded them to the internet archives) as the show claims. NASA scientists explain the the sounds as interference with the VHF ranging system, which is integrated in the radio system. The sounds are characteristic for modulation effects on an oscillating circuit like you would have in a theremin.
The sounds also sound completely different as you can hear here on the original tapes (beginning at 2:50):

http://history.nasa.gov/ap10fj/audio/a10o-1021010.mp3

Neither the Crew, nor NASA ever showed real interest in the phenomenon.
Apollo 10 Lunar Module Pilot Gene Cernan:
‘I don’t remember that incident exciting me enough to take it seriously. It was probably just radio interference. Had we thought it was something other than that we would have briefed everyone after the flight. We never gave it another thought.’

This whole show is utter sensationalist bullshit...

Oh dear, i really wish they would stop doing the "Michael Bay" approach when they make these documentaries, spooky music, the "movie voiceover", the cutting and adding drama etc etc. Its science, we dont need it to be fancy, it already is fancy!

Oh i know this. This is a famous example given in wave optics courses.

Basically if you've got any sort of EM radiation, whether it may be light, microwaves or as in this case, radio signals you also have some sort of diffraction phenomena when passing through apertures, or more generally at the edges of obstacles along the path.

Some part of waves (radio signals) can go behind obstacles and your receiver does not have to be in direct line of sight of the transmitter to receive the signal, that is how you can send broadcast signals to the other side of a mountain down on earth.
But here is the problem , due to the interference of multiple waves ( multiple signals being transmitted and the waves being diffracted off multiple places (e.g. right/left side of the moon)the signal you receive behind the obstacle is not necessarily the same, in most cases it is some sort of randomly distorted signal you receive. So the outer space music they are hearing is actually earth music on the radio its just that by the time it reaches the other side of the moon the signal gets so weak(distance) and distorted(interference) you end up hearing some random sound.

You get an analogous phenomena if you switch diffraction with reflection and radio signals with sound waves, go to a big shopping mall and just listen to that weird growl in the background. That is actually just loads of people speaking and the interference of the sound waves turning it into that weird mall noise.

If anyone's interested in how the same phenomena is used in optics just google "diffraction gratings"