The Musicmap web site looks, at first, like a cartoon streetscape, like a Lego Emerald City of Oz. But start mousing around and you realize it's actually an interactive infographic that maps the definitions, relationships, and sub-genres of the last 146 years of pop music.

The result of seven years of work by a polymath Belgian architect named Kwinten Crauwels, Musicmap is almost overwhelming in its comprehensiveness. Genres are color-coded (blue for blues, gospel, and jazz; yellow for rock; red for electronic). Six different kinds of dotted lines show different relationships among 234 sub-genres. Click one, and a description pops up next to a YouTube playlist (with Spotify coming soon).

The inspiration? Crauwels wanted an online overview of music and couldn't find one he liked. "I find art very important," he says. So he started checking out library books to teach himself data visualization for music. He started making map after math, and eventually got his brother, a programmer, to build the website.

Seven years after he started, Crauwels' "Genealogy and History of Popular Music Genres from Origin till Present (1870-2016)” is a ride worthy of the Magic School Bus. The further you dive in, the more detail you see. It's nonlinear, just like music itself. “You can never create the ultimate genre map—there is no such thing, because it’s a sociological reality, not a scientific one," Crauwels says. "But you can at least create a very good approximation, so people can learn more.” He's right; Crauwels has built a chart that's actually chart-worthy.