I was looking for similar projects with DIY hardware so I am starting a little link collection. I started looking because I think I might want something with better audio than a Toniebox to use it for music. I hope if anybody has links they will add it here as well! 
- The ESPuino project: GitHub - biologist79/ESPuino: RFID-controlled musicplayer powered by ESP32 and https://forum.espuino.de/
- https://medium.com/@charlesv/making-a-raspberry-pi-based-rfid-music-player-e3885919368b
- nfcAudio - WiFi enabled MP3 player with NFC capability
- https://www.instructables.com/Juuke-a-RFID-Music-Player-for-Elderly-and-Kids/ (aka Easy-To-Use Music Player Relies On RFID | Hackaday)
Moving these down here because they seem like low quality generated websites: