Ideas for Business Cards

See also:

• https://www.instructables.com/id/PCB-Touch-Piano/ Teensy USB MIDI Cap Touch Piano
• https://calcium3000.wordpress.com/projects/teensy-midi-interface/ Teensy USB to MIDI Interface
• https://mitxela.com/projects/stylocard The Stylophone card
• https://division-6.com/products/business-card-synthesizer/
• https://division-6.com/products/business-card-sequencer/