As I've been explained, #mastobada comes from the game Shabada (which can be played at parties in France at least), but the mastodon version ( #mastobada) can be played without any cards or score keeping; every Monday around 9 am, the account @mastobada shares a new word, and the goal is to find songs related to it, ie. the word appears in the singer/band name, in the title, in the lyrics, and can be translated if needed.
Then everyone can post their picks on #mastobada with youtube links !

There's also a system (I don't have the link, though, but others can share) that enables to listen to all the shared songs as a radio.