I've been looking for ways to restore some kind of physicality to my digital music collection, and this has led me to create a setup using a square Moo 'album' card with NFC tag sticker, to trigger an iOS shortcut and play an album to an airplay speaker with the least amount of friction.
There's nothing original here, people have been doing this for years, most notably Brendan Dawes with his Plastic Players 1 & 2. I'd considered using a Raspberry Pi + NFC reader add-on, but as iPhone's since the XS/XR can read and write NFC tags in the background, I went that route. Using a device that's always with me (rather than maintaining a screen-less Pi) is the most frictionless way for me to do this.
Leigh videoed me demonstrating it to her, but sadly the airplay connection didn't work then (more on that bit later). What follows is an explanation of how I've done this using iOS, the different approaches you can use, and the pros and cons of each.
You can then either write the information to the NFC tag, or use it to trigger an iOS Personal Automation. The former works for everyone, but you have to OK a dialog prompt. The latter can run immediately, but only works on that particular device. I went with Personal Automations, but here's a run down of both methods: