There has been so much experimentation over the years from bands, that used emo vocals and done to, punk, metal, hybrid punk/metal etc but it is really a style of vocals and was used extensivly by the hardcore bands to articulate the hate/rage end, punk to articulate anger and later bands used the vocal style and hybridised it with guitar rock/pop which is where emo are probably today.. a journey that is never ending.. that is the blessing of Rock!