Call it the original space jam:
The "song" was detected by a magnetometer experiment on Rosetta as it approached the comet and deployed the Philae to land on its surface.
ESA said the music is oscillations in the magnetic field in the comet’s environment.
Scientists believe it's produced by the comet as it releases particles into space, which are then electrically charged by ionization. However, ESA said in a news release that "the precise physical mechanism behind the oscillations remains a mystery."
“This is exciting because it is completely new to us. We did not expect this and we are still working to understand the physics of what is happening,” Rosetta Plasma Consortium principal investigator Karl-Heinz Glassmeier said in the release.
At 40-50 millihertz, the song falls outside the range of human hearing so the agency boosted the frequency by a factor of 10,000 to produce the clip you hear above.
It's somewhat reminiscent of Floyd's "Several Species of Small Furry Animals Gathered Together in a Cave and Grooving with a Pict."