I had a set of cds that went with an intro to music theory textbook around ~2009. It did also made heavy use of indices in tracks to do exactly the same thing. My car stereo listed each index as a track.
I wish I could remember the name of the textbook because I really liked a lot of the baroque music on the CDs and can't remember who they were by or the titles of the songs...
Do you remember if the textbook was orange (possibly with a two-tone cover design)? I had a really good textbook in college that had a... 4? CD set (with the big jewel case) that had a bunch of tracks and like you I really enjoyed it.
It was a reddish (could be orange, could have been maroon) color lightly mottled in black with a picture of a violin (or cello, idk) set in the lower 2/3 of the cover. I'm somewhat certain it had 6 cds because it filled my disc changer in my stereo, although that detail is fuzzy too.
I wish I could remember the name of the textbook because I really liked a lot of the baroque music on the CDs and can't remember who they were by or the titles of the songs...