LinuxMusicians

It's really great.

https://www.youtube.com/watch?v=NYjFP8gildU

Good video and performance but audio quality sounds like they shared mp3s and converted and resampled them several times before mixing. Or maybe Zoom audio? Singer looks like James May!
I loved prog rock in the 70s (it was just "rock" then), Yes, King Crimson, Jethro Tull, but Gentle Giant never caught my attention.

I like this one that popped up in my sidebar - Camel - Lunar Sea (Live) https://www.youtube.com/watch?v=TakazuzJVPc

Too many singers. It sounds chaotic, which is a bad thing for a Gentle Giant tune as their songs tend to have some abrupt changes.

Here's one of my favorite progressive rock tunes:

https://www.youtube.com/watch?v=0Fd_7unOj4A

P.S. If you like Camel, I think "Snow Goose" is their best work.