Cosmic interference
My band practices at a place in Derby called The Snug; it's a practice room downstairs and recording studio upstairs. Next door is Derby Gaol, site of many a hanging, incarceration, murder and general despair such as the famous Derby Ghost Walks.

One night, we were at The Snug, recording guitar parts for the forthcoming Skullfunk album. Present in the room were myself, the drummer and the bass player, as well as the future Mrs Kenny Martin & her daughter.

We were just about to record a take when we realised that my amp was picking up a radio signal. Not unheard of, although fairly unusual in this instance since I wasn't using a wireless system.
Gathering round my amp to listen and see if we could tell which radio station it was, we were decidedly chilled to hear what sounded like mediaeval monks chanting. Faintly at first, then it started getting louder... a quick check confirmed that it was indeed coming from my amp and not from some reenactment going on outside; then it stopped.

Spookiest of all, we'd started the recording ready for me to play the take, then heard the sound. Playing back the take, the monks weren't audible - all you could hear was us talking about it.
(Professor Kenny Martin Hmm? What?, Mon 17 Sep 2012, 13:56, 2 replies)

My dad used to pick up truckers on his massive organ
... so I know about this.

Basically, a dodgy solder joint can act as a radio receiver diode. It's the same principle as a crystal radio, where a fine "whisker" wire contacts the crystal. My dad used to play a large electronic organ (keyboard), and we would often be startled by bursts of CB radio blaring out, having been picked up in this way.

Presumably the pickup was downstream from the output to the recorder, which is why it didn't record.
(moon monkey is busy making memories worth repressing, Mon 17 Sep 2012, 16:27, closed)

Totally with you on this...
...except the recording. That was being done by means of a microphone placed in front of my amp. Therefore, anything we heard coming from the amp should have been picked up by the microphone. Most odd
(Professor Kenny Martin Hmm? What?, Tue 18 Sep 2012, 0:38, closed)