Master rights

Every commercial track carries two copyrights. One sits in the song itself, held by the songwriters and their publisher. The other sits in the particular recording of it, and that is the master, usually owned by the label that paid for the session, or by the artist on an independent release.

Using a track in a video means clearing both: a sync licence from the publishing side and a master use licence from whoever holds the recording. That split explains something creators find baffling, which is one song producing two separate Content ID claims from two different companies. Recording your own cover sidesteps the master entirely and leaves the publishing side exactly where it was.