Amazon.com: MIDI Shield Musical Breakout Board Instrument Digital Interface Adapter Plate for Compatible Arduino Adapter Board Module : Musical Instruments
GitHub - nicholasbester/arduino-keyboard-instrument: A Keyboard instrument made using pushbuttons and a piezo speaker on an Arduino http://www.nickbester.com
MAX485 TTL to RS-485 Instrument Interface Module for Arduino - Walmart.com
Simple note” an Arduino musical instrument | Physical Computing 2010
Amazon.com: MIDI Shield Musical Breakout Board Instrument Digital Interface Adapter Plate for Compatible Arduino Adapter Board Module : Musical Instruments