Simpsons Meet Metallica

I couldn't let this cameo by Metallica pass unnoticed. Both Legalbgl and I are big Metallica fans, having seen them quite a few times each, including at Woodstock '94.

Bonus points to those who note the song Metallica closes their cameo with (not that it takes a lot of work to figure it out). I figure that anyone worth their mettle will have the answer within about 5 seconds of listening to the clip.