The OCD part of my nature makes me look for patterns and connection. That's actually a normal human trait. We categorize things to better understand them. It also gives us an instant context to communicate with each other. We tend to assume that everyone has categorized things in a roughly similar manner, but often forget to ask whether the category itself makes any sense.
Musical categories, for instance, seem inherently weak, especially when it comes to styles that are still evolving. That's largely because there are so few pure musical genres. Sure, with insulated groups, there's a sense of musical style sui generis, like Appalachian bluegrass or Swedish death metal. And yet, even these are tethered to roots that have spawned countless other styles. It's hard to find purity; there is no vacuum.
Over time, many stylistic labels become useless on their own: rock, jazz, world music...because the label represents a melange of vaguely related instances. We sense the relationship between two sounds, but can't really articulate the details. So we fall back to the general name. Rock has come a long way since the '50s, but even in the early days, elements from other styles, like country or blues, intruded. Like any hybrid, a given musical sound can be healthy, varied, and strong from taking pieces from numerous sources to create something unique.
For me, the most interesting music happens in those odd spaces between genres. That's why I love bands like Gogol Bordello, Camper Van Beethoven, Dengue Fever, Easy Star All-Stars, Nouvelle Vague, Whiskey Blanket, and Béla Fleck. Picking a genre in these cases seems pointless; it's better to list their antecedents. The music is vibrant and compelling, but the labels (e.g. jazz-bluegrass or gypsy punk) don't really make the grade.
Unfortunately some people get too hung up on labels. They can argue about whether something is "really punk/reggae/etc" and discount artistic value because it's not a pure enough example of something that was poorly defined in the first place. There are whole styles of music that I thought I didn't like, such as bluegrass or heavy metal. Eventually, though, I encountered examples of music I found I did like when I stopped worrying about the label. Occasionally, it even opened up my ears to the style in general. Now, I don't necessarily like everything I hear, but I can focus on what it is I don't like rather than automatically dismissing it.
So now, instead of satisfying my need for pattern and connection by sorting music into genres, I look for the patterns relating a given performer or song to other things I know. I can wonder which of those connections are real and which are just coincidence (or too removed to track). My head doesn't have a set of bins, it has a web.