Nice execution! I made something similar a few years ago, except it generated a playlist of previews from iTunes with an option to connect Spotify. It worked by finding all venues within a certain radius from you using the Foursquare API, and correlating that with the JamBase and Songkick APIs. It was a bit ahead of its time because not enough people had Spotify, and their catalog wasn’t big enough to cover artists coming to some of the smaller venues. I might still own the domain rockout.fm if you want something a bit more catchy.