[brianwhitman]

These genres come from people talking about music using whatever organic / natural words they use to describe music. We've done the work to map those into single-term "genres," as it's been shown many listeners appreciate the flat categorization. There are similarities between genres in the API, so you can quickly see which genres sound like others.

[edj]

it's been shown many listeners appreciate the flat categorization

Huh, that's interesting. Did you discover that with internal analytics or a survey, or an outside source?

If it's something internal, you could blog about your discovery. It would make an interesting read for us music nerds.