With a name like Megadeth, you better be in the midst of a cross-country Gigantour. (Sponsored, fittingly, by Hot Topic, the store of choice for angst-ridden teens.) It’s hard to believe the thrash metal band has been around for nearly three decades, but oddly enough, they’re practically a nostalgia act now. After breaking up a few years back, the semi-original lineup reunited and released United Abominations. Also playing: In Flames, Children of Bodom, Job for a Cowboy, and High On Fire. 6p.m.