-Long story short: It’s a song.
-Short story made long: “La Sandunga” or “La Zandunga” is a traditional Mexican waltz, and the unofficial anthem of the Isthmus of Tehuantepec in Oaxaca.
The true meaning of the word is uncertain, but has its origins in Zapotec languages. Some say it translates as “deep music”, others as “graceful, happy, dancing woman”, others as “perfect party”. Anyways, Sandunga is uproar, jauntiness and bliss… Give us more Sandunga, please!
Yeah, my rhymes suck…
… And that’s the story behind the Sandunga invocation everywhere.