You can load any youtube music song on youtube by just removing the "music" subdomain.

Then why do you say they might not be the same files?

	▲	charcircuit a day ago \| parent \| next [-]
		Let me start over. Youtube itself has DRM required for certain videos, and certain formats of videos. The 256 kbps format for music will be protected by DRM. If you do not have DRM available youtube will fallback to a lower quality format to play the auduo.
	▲	sgtlaggy a day ago \| parent \| prev [-]
		Music might have higher quality audio-only files as provided where Youtube might have it combined with video and a generic compression algorithm applied as with all other uploaded videos.