Issues importing an itunes library from High Sierra into a new Apple Music library (Big Sur)

I imported my long time itunes library from time machine onto a new m1 macbookair running Big Sur, and am finding that many of the files that previously worked fine are simply not playing - not only in Apple Music, but even in the finder. I've gone through the music folder and am unable to play them in preview and when I try to open one of the mp3s in quicktime i get a message saying that I "don't have permission to open the document." This is not a file I downloaded through iTunes, I ripped it from a cd. I've never had an issue playing it before. I tried using get info and changing permissions and it lets me change everyone to read and write but that doesn't make any difference. Any ideas how I can get it to work? It seems to be a random assortment of albums from my itunes library that don't work, and things that were added to it longer ago. Thanks all!