Thrash is a kind of music that started its figth in the ending the 70's and the beguining 80's when some bands of metal began to blend punk and harcore old school, however is dificult to know how thrash arise becouse there are so many theorys about it.but the true thrashers think this appeared
in usa's streets when punks and bangers join themselves to play against the bad acttitudes of society ,govermental problems and facism. The thrash arise up in diferents states of USA in this case one of the most important appeared in california and it is called thrash bay area with bands like vio-lence one of the most important band of underground ecene thrash.