RE my message above but one - to clarify, for "recordings (audio and/or video) of professional and semi-pro performers" I mean original recordings I have made - generally from the audience and/or the soundboard for audio. Usually without asking permission I'm afraid. Anyway they presently repose in my archive but without further action will probably go to the tip upon my demise... which does seem a bit of a waste to posterity.
By contrast, historic audience and soundboard tapes of some of my favourite bands and performers (think early Fairport, Sandy Denny, Albion Band and the like) have made it into the public domain via bootleg issues or tape sharing sites which is all the better for history, in my book, though I very much doubt that any permissions have been sought from the artists and/or composers involved.
Regards - Tony