I love those like seven minute Metallica songs where there are structural changes that happen in the song, almost like different acts of the song rather than being one act.
Discussion
https://open.spotify.com/track/51h0JFw6R8LQIB9q0GVdmG
Actually multiple covers with great transitions, but this song does come to mind 🤘
If you like that style of metal may I recommend Iron Maiden.
Same. And Justice For All and Master of Puppets were phenomenal albums (same with for Ride the Lightning). For more recent, I like Avenged Sevenfold. They have some great long song with lots of structural changes (single: Tonight the World Dies)