::No, Chris, you can't just call something waves and that makes it so. It is a very common term used to describe certain related forms of music. But since no sources are provided that establish that these three types of emo are related in that way, use of the term qualifies as OR. Waves of feminism or punk, for example, can be established in primary and secondary sources (you know, books and academic papers). The ones in this article cannot. And while I know Google is not the be-all-end-all of inclusion, a quick search of "the first wave of emo" spits out nothing but blogs, reviews, etc, most of which cite this article as their reason for calling things first wave (most quote sentences from here wholesale). That doesn't make sense - Wikipedia is not supposed to be a primary source, and use of this term qualifies as OR. There are plenty of other ways to word this article, and indeed, it would be simply enough in the headings to just use the year labels that are already there..