Have you ever used Spotify Running? It will detect your running tempo and find music that matches your speed/rhythm. It's really cool! I haven't used it in a couple years (because I got lazy) but hopefully it's still around.
It's definitely still around and I absolutely love it. If anyone is interested, you can read more about it here. They even have some unique remixes they've made just for your running pleasure. I've loved what I've heard from them so far!