I might be playing acoustic shows this summer, but I'm a metal guy at heart. And I'll tell you the comeback of the year: Swiss metal warriors Celtic Frost! Because they haven't made a record in so long, this is a band that you may not have heard of ­ but it's not often that a group can take a fifteen-year hiatus and come back with a masterpiece. It's called Monotheist, and I can't remember the last time I was so excited about a record coming out ­ I was at Tower Records at midnight! (I'm joking,...