My new favorite song — played and replayed umpteen times over the past day is a simple, fabulous acoustic-guitar Lady Gaga medley by Sam Tsui and Kurt Hugo Schneider. Heard of them? Maybe not, but ...

Tenacious D is known for its lively rock songs and its blend of comedy and heavy metal, played through acoustic guitars. But the band, comprised of Jack Black and Kyle Gass, performed two epic covers ...