just like u, before that i like to play heavy metal song like metallica, nirvana and i thought metal is the most difficult. but that is wrong, because each type of music have its own difficulties. I try to play jazz music n classical music, i found that both of them are more challenging than rock metal music. so if u have chance, do try to play other types of music, u ll realize a lot. If really want to explore more on metal, try to play dream theater song. try on off beat music