Still fleshing out the desired features for the device: suggestions very much welcome. 

Core functionality has been laid out:

• 8 tracks
• 24 Keys
• 8 knobs
• 2 Shift/Alt keys for alternate input functions
• Track control (Play, pause, record, etc) 
• Touch screen
• SD card sample loading
• Bluetooth device pairing for wireless MIDI control and expansion controllers

SAMD51 core processor

(testing with Adafruit Grand Central M4)