> If there is an error-free automated way to tag them all, great
Picard has built-in acoustic fingerprinting, which is mostly error-free, but they don't have fingerprints of all the tracks.
For the rest, yeah, Picard assumes it can find *some* information from the tags. If it doesn't, I guess it'll be lots of manual work. Maybe someone has written a plugin to parse filenames, I don't know.