I left you a message on Twitter. Unfortunately it didn't work for me on my N9. I tried out a couple of popular songs (from Gotye to The Beatles) and even the one you use in your preview video.

I see in the video that you were testing it on a N950. Could it be that the N9 microphone doesn't record?

Otherwise great idea, an app which could make a couple users very happy (despite the not so big (yet) data collection of echo nest)