I beg of those of you who love metal and all its crap sub-genres, listen to some jazz. Not Kenny G, he's not jazz. I mean John Coltrane, Thelonious Monk, Charlie Parker, those bebop cats as well as swing era shit like Ellington, Count Basie, Benny Goodman, Chick Webb, etc.
Listen to Giant Steps by John Coltrane. The changes and harmonies will make your head explode.