Guys, I think I found out about that Black Lips song.
I just looked up NPR's full playlist for tonight's All Things Considered where the Black Lips song is airing (
http://www.npr.org/programs/all-things-considered/), and there is a Black Lips song on there, but it's New Direction, one of their older ones (looked that up too).
That bit with Ke$ha NPR was talking about in the written article wasn't about an actual song. If you listen to the interview part "Marooned In L.A. For A Week, Coachella Bands Make Do", in the playlist that's right before the Black Lips song, and skip to just after 3:50, you'll hear the part with the Black Lips.
It's not a real song, that article from earlier and the stuff the Black Lips tweeted was just about the Black Lips and Ke$ha hanging out together and goofing around at Coachella, they were doing animal noises and were clearly joking. So yes, IT IS ACAPELLA naturally.
BLACK LIPS TROLLIN