Awesome. The first thing I did was run my finger across the qwerty row from left to right, which immediately made me think of Toccata and Fugue, prompting me to pick out this excerpt:
Transposed down a half step to D-flat minor to better fit this thing's range. It's not a perfect transcription by any means (the arpeggio suffers from limited polyphony, for one), but it's pretty cool that it was so easy to get this far!