It all starts with punk rock, see, and rock 'n roll. From rock 'n roll spawned a style of music called "hard rock" which is basically rock 'n roll but deeper. When hard rock is blended with punk rock, we get
hardcore rock which essentially pre-emo punk rock with heavier rhythms. Also spawning from rock 'n roll and classical music we get metal. Now, when we blend
hardcore with metal, we get "metalcore" which is
hardcore but with harmony elements and the occassional guitar solo. Now it gets complicated. When we blend hard rock with metal, we get thrash metal. If we take thrash metal, add some more emo and
myspace, and blend it with hardcore rock, we get "post hardcore" which can very very easily be confused with screamo. The main difference between post hardcore and screamo is that in post hardcore, the singer still "sings" but doesn't go into a crying
fit at some point during the song. Now, there is one more style that is left un-discussed. A style called "hXc'
mo" (prounounced "aytch ex see
mo". I'm not quite sure, but I think that hXc'
mo is the product of blending screamo and post hardcore...that's the only logical way I can figure this shit out.