Comment by Scaevolus

Aside: if you want a source of high quality Piano MIDI recordings, you should check out the MAESTRO dataset: https://magenta.withgoogle.com/datasets/maestro

> The dataset contains about 200 hours of paired audio and MIDI recordings from ten years of International Piano-e-Competition. The MIDI data includes key strike velocities and sustain/sostenuto/una corda pedal positions. Audio and MIDI files are aligned with ∼3 ms accuracy and sliced to individual musical pieces, which are annotated with composer, title, and year of performance. Uncompressed audio is of CD quality or higher (44.1–48 kHz 16-bit PCM stereo).