The link below leads to a site that is known as 'Wolfgang's Vault':
Free streaming live music, Live concert recordings, Live music downloads, Classic rock concerts
So, what is so special about it? It offers rare and interesting concert recordings, for just about every influential musician you can think of. What's more, it's legal (and that is the real revelation). For once, it is possible to register for a free account and listen to your fill of hard-to-come-by music; without having to worry about going to jail for copyright infringement!
It seems far too good to be true! The website works because the artists are paid or compensated, every time the music is streamed. Also, I think the website buys the legal rights to use the music. Still more of the content can be bought by individuals and used.
The music that is offered not the usual mainstream, popular stuff, either. These were significant and historic (or just plain good) gigs. Everyone, from Jimi Hendrix to The Grateful Dead; to Van Morrison to Muddy Waters, to Neil Young; is listed. Each artist seems to have several shows to their name, at least.
I can only hope that it is, indeed, as good as it seems to be.