BotW endgame music spoilers
The composition for the music in Hyrule Castle really is incredible. On the inside, at one point the music very subtly turns to a re-arrangement of the Ocarina of Time music, but in the wrong key and with some of the cords with off notes.
The, outside, the music at one point starts redering the iconic LttP theme in soft violin... for *five* bars before trailing off. It's dang disconcerting.
BotW endgame music spoilers
There's also the part in the horse riding music where the LttP theme starts playing in the background of the track, just for a moment, so soft and gentle you'll probably miss it.
And, to be clear, the composition is incredible in its own right, not just in terms of musical callbacks.