I urge you to consider uploading some music. Your project will then reach several orders of magnitude more people.

If you want to keep yourself honest (and not be accused of picking out the best ones), generate some (e.g. 10) without listening to them, and upload them directly.

would be interesting to integrate it in a running app. the more quick the runner the higher the music tempo and vice versa.

It takes at most 5 minutes for you to make some sort of recording and share it. Why would I spend potentially hours gathering MIDI files and setting up a development environment without at least a small sample of what to expect?

Edit: better yet, just set it up as a web service.