I was able to speak with public domain representation regarding the status of these music albums.
The response I received was the hack at Archive.org must have caused an incorrect file merger.
The difference is, when the audio was archived the files must have been incorrectly merged on archive.org leading to multiple ip addresses being assigned to one url.
File with an uploader in a music collection were shown as "license selection" on some file saying what the public domain release was.
Other files and pages were released under "Open Source Audio" including artists like "Metallica" whose albums are now public domain.
On the archive what you get is a list of 2.7 Million listings under "Open Source Audio" that the music company has allowed to be on the page.
Other's were listed as a "Creative Commons License Page" under a more specific listing.
The bulk of the albums and artwork were released as "Open Source Community Collection".
What that means is, there is a server error on archive.org I was told, they mean probably happened, with some albums listed under "community audio" open source and some under "creative commons license".
The final word was, some titles said "public domain" under the album, while others like "Metallica" were listed under "Open Source Audio" at the top of the page.
Apparently, these were not merged...but they mean if the Public Domain Archive at archive.org holds an album / image then it is DEFAULT set to "Open Source Community Audio" with artwork and other's says "Creative Commons".
The point is the amount of work to maintain the archive is non-profit plus the page was hacked.
So you get like this:
Some albums say "Creative Commons" then rest listed next to them say "Open Source Audio" with the album artwork with no details.
"PBS" means, if it's on the archive then it's public domain, but most are just listed under "Open Source Audio" 2.7 million listings with only some under "Creative Commons" which is just a SUB SECTION of the public domain "Open Source" audio section where all the album covers are listed.