There are so many callbacks to previous games, but it is all done in such a subtle way. Zelda's theme while you're riding at night, the Temple of Time's theme completely broken and sparse when you visit the ruins. I love Hateno Village, Kakariko Village, and Tarry Town's themes. It's particularly cool how Tarry Town grows with each new addition to the town adding new instruments onto the theme. And Hyrule Castle's song is my favorite in the game. I've found themes from at least 2 previous games in that one song alone, but there are probably more. I think the soundtrack is a super underrated aspect of the game.
https://www.youtube.com/watch?v=lVDGXXIq4b4