This set of videos, via Voltage Control Lab, is an unofficial tutorial on using alternate firmwares with the Music Thing Modular Radio Music Eurorack module.
The standard firmware for the Radio Music lets it be used for voltage-controlled playback of audio files. Alternate firmwares let you use the Radio Music as 808 drum module and more.
They also shared a tutorial that demonstrates how to prepare new samples for the Radio Music module:
Details on the Radio Music module are available at the Music Thing Modular site.