Available on audible:
https://www.audible.com/pd/How-to-Listen-to-and-Understand-G...
It's long (36 hours, broken up into ~45min lectures), but very engaging and accessible. He goes through the entire history of Western music from Pythagoras through the 20th century. He covers everything from (very basic) music theory to how trends in society and technology influenced the music that was produced in each period.
After listening to the whole thing, it gave me a much more fully formed mental model of how different eras, composers, and styles relate to each other.
And from there it's become much easier to dig in and appreciate different areas of the repertoire, rather than idly trying to absorb disparate pieces that would come up on radio/streaming.