How to correct the exclusion list for Time Machine backup? Music is not listed for exclusion, but is excluded
These are not the files from the exclusion list but files that have been directly marked as excluded in their extended attributes.

For example:

$ xattr "/Users/foo/Music/iTunes/Album Artwork/Cache"
com.apple.metadata:com_apple_backup_excludeItem


Most of these seem to be logs, caches or indexes that can be rebuilt.