Glitterbeard 2021 - How DID they do it?

The clues are in the books you find.

@wcpsycho He played shanties with many of the Pirates he met in the journals. They each had favorite instruments and the clues somehow point out where to stand and such. It’s very interesting!

I think I was one of the first to do Glitterbeard on Day 1. I previously figured most of it out on Insider (ie. the song needed, the whereabouts of his tree, the fact that there were 8 spots, all from the journals.) So on Day 1, I convinced many players in the server to do it, but what I didn't know that first day (since I never had many people in Insider), was that it needed specifics instruments in specific spots. It took us awhile, but once we discovered it (the lights would glow brighter and longer with each right instrument), it was one of the most glorious things in the game. I've only done it once, but would love to do it again someday. But that's how I figured it out.

Rare announced it...Rarethief did the rest.