wikipedia cofounder dr. larry sanger on the establishment takeover of wikipedia, corporate control of online knowledge,

So you are right. Partly because of the sheer technical difficulty of archiving everything, first of all. And partly because some people have a vested interest in taking some information down. Like if there's some big, faceless corporation hosting a gamer community full of extensive chats, and the gamers made relationships, and there's like a whole history they care about — nobody else cares about it, but they care about it — there's just some people in a boardroom somewhere who will say, ”Oh, well, we gotta shut down this website, it's not making any money anymore.” Usually for legal reasons, they'll just take everything down entirely. And, right, when you were a kid, you weren't thinking about that — that maybe the only thing that would keep information online is the people who originally put it there.

The Internet Archive maintains an enormous Live Music Archive of concert recordings, not all of them by the Grateful Dead.

https://archive.org/details/etree?tab=collection

In addition to Rusted Root and the Grateful Dead, you can stream or download a wealth of recorded live shows from bands like Little Feat, Blues Traveler, My Morning Jacket, Los Lobos, and the Smashing Pumpkins, as well as singer-songwriters like Warren Zevon, Elliott Smith, Jack Johnson, Robyn Hitchcock, and John Mayer.