I don't have the energy to do a proper writeup right now but the code for qrplay is complete: https://codeberg.org/nupanick/qrplay
this is an app by @SArpnt and myself. it generates a QR code. when scanned, the QR code contains the full text of a website, in a format you can copy and paste directly into your URL bar. that website contains a JavaScript app that plays the musical notes of your choice, using an easy to edit text format.
tl;dr: chiptunes on business cards. go wild.
edit: comments appreciated! did you print one of these?
