The visual below shows how often each key gets pressed relative to the rest for a given piano piece. It is a piano-looking histogram, so I named it a Pianogram! You can take a look at the pre-loaded options, try uploading your own piano songs (MIDI files only), or download the pianogram as a PNG image. Enjoy!
![Pianograms - A Visual Experiment by JoeyCloud](https://cdn-ak-scissors.b.st-hatena.com/image/square/711b5e0ce972651d1e4983d6ed48122e69fb360e/height=288;version=1;width=512/http%3A%2F%2Fi.imgur.com%2F06OLg6h.png)