Hi, mribob,
For music file conversions I use
dBpoweramp, which has some useful metadata editing tools. Plus it’s a great CD ripper. It’s not free but it works really well and is highly regarded by a lot of audiophiles.
I’m not sure how or why you ended up with music files without any metadata. Are you sure the files don’t have some information? Track title and track number at a minimum? However it happened it was probably a big mistake but I did find an application that might work to reestablish the missing metadata:
MusicBrainz Picard which states that it "uses
AcoustID audio fingerprints, allowing files to be identified by the actual music, even if they have no metadata." I didn’t bother downloading it and trying it out so cannot say if it’ll work well for you.
I also use
Mp3tag, which has some powerful batch editing features and can add metadata for missing information. But I haven’t used that feature yet.
As for FLAC files not being a reliable music file format, that’s not what thousands and thousands of serious audiophiles would say. You can argue about relatively meaningless technical details but FLAC is one of the most popular uncompressed file formats for a good reason.
Good luck!
Tom