Have a look at the Rock Band 3 keyboard & MIDI PRO-Adapter | Engadget
GitHub - FromtonRouge/eProDrums: Rock Band drums midi software. Adds real flams, advanced hi-hat control, ghost notes and other features to the Rock Band game
Convert Rockband Controllers To MIDI Drums #MusicMonday « Adafruit Industries – Makers, hackers, artists, designers and engineers!
Guitar Hero and Rock Band drums combine for ultimate MIDI kit (video) | Engadget
How to Setup Rock Band Drums as MIDI Drums in Cubase | BassGorilla.com
Amazon.com: Rock Band 4 Wireless Pro-Drum Kit for Xbox One : Video Games