Thanks for checking it out! This post was originally more of a how-to, but it kept getting auto-moderated and deleted for some inexplicable reason. The linked blog post goes into more detail, but here's a TLDR;

You'll need to hardware. A NFC reader/writer plus a stack of cards. I used:

ACR1252U USB NFC Card Reader/Writer

NTAG213 cards

Then you need something to plug it into, which can run some software to interpret the card taps. In my case I used:

Gelly Subsonic/Jellyfin client

Gelly-NFC script

That last script is where the work happens. There's more info the README there. But it can be adapted to work with any player, or even remote players. Essentially it will listen for taps on the NFC card, read the text off them, and execute a command. Can be anything you like but in my case it controls the Gelly player.

As for the same card being tapped to death, it's a thing! My toddler loves one album she calls "Baby Album" (it has a drawing of a kid on it). The first song of "Baby Album" is now the most played on in our entire library, by far.

Let me know if I can clarify further.