I would think some performances will survive just because they're that good. Iconic.

I think there's a shelf life even for those. They're "iconic" within their cultural setting, but after a while that cultural setting is just no longer relevant.

There were iconic performers and performances, that were just that good in their time, back in the 1920's, 30's and 40's. But they're just not of much relevance to modern audiences, who aren't necessary firing up the youtube to watch Al Jolson or Count Basie or even Bing Crosby's old performances. At least, I don't think they are - maybe I'm wrong on that. Bing Crosby was the Beatles of the 1930's, who absolutely revolutionized popular music and dominated it (and culture more broadly) to a degree that no one had before...and he's basically disappeared from musical cultural relevance except as an artifact of Christmastime.

I wonder if performers and performances can last much past 80 or 90 years - basically when the last of the audience you built through the end of your mainline popularity have died off. Maybe changes in the style, production, and recording technology of popular music will just have moved too far past where you were for you to continue to be of interest to a modern audience, save when looking back to study past influences? Few of the big pre-WWII megastars seem to have held on. Even the iconic ones.