I don't think you'll find I ever said vocals DETERMINED genre, but they definately have an affect. Think of melodeath and you think of growling/screaming vocals, that's just how it is. Similarly, think of rock and you certainly don't think of such extreme vocals. You've named one case, but it's hardly the norm for jazz bands to have screaming vocals, is it? There are exceptions to every genre(In Flames aren't the exception to hard rock, btw). Point is, Anders vocals are still extreme enough that most fans of hard rock would be turned off by In Flames, no matter how their songs are structured. I think one of the boys of In Flames said it best when an interviewer asked "is the new record metal?" and he answered an emphatic (and slightly incredulous) yes, clearly wondering how such stupid questions could be asked. In Flames are still metal, and no matter how many people would love to say they're not anymore, they are.