Fairport, Fotheringay, Ewan MacColl & Peggy Seeger whose catalogue has been mined by all the others, Kirsty MacColl and the Pogues, Steeleye Span, Pentangle, Richard and Linda Thompson. Mostly live clips. Very roughly chronological, with branches and flashbacks. Examples here of Ewan MacColl songs are Eppie Morey (Fotheringay) and Cam Ye O'er Frae France (Steeleye Span, for lyrics and glossary see: www.informatik.uni-hamburg.de/~zierke/steeleye.span/songs/camyeoerfraefrance.html) The two Ewan MacColl clips are the only ones on youtube, and only the first shows Peggy Seeger.
There's not much live Sandy Denny footage. There are more live audio clips which I didn't include except for #2, a Dylan song, and even better than the original studio recording. I included one Fotheringay live clip (#6). Clip #14 is of her song "Solo" which is gorgeous, with superb backing by Fairport, but super fuzzy b&w video.
Jerry Donahue was the lead guitarist for Fotheringay, and came with Sandy back to Fairport. He is in clips 6, 7, 8, and 14. He has two really sweet solos in clip 7 from a recent Cropredy festival.
Fairport asked Chris While (from Albion) to cover Sandy's vocals when the "Liege & Lief" lineup reunited to perform the entire album at Cropredy. She has joined them on other occasions too. She is in #7 and the last one #30. Crazy Man Michael closes Liege & Lief, and this playlist :-) I assembled as much of that show as I could in a separate "Liege & Lief" playlist.
Clips 1, 3, 4, 14, 30 show up in several versions of the same source material. Other songs show up in different performances - that's true for all the Richard & Linda Thompson, Steeleye Span, Pentangle, and Pogues. These are the best versions I could find.