I teach K-12 Music, and every job has one or two classes that continue to exceed your expectations. Yesterday I taught one of mine. I had a very long, complex rhythm written on the board. I was expecting them to read the first line, but they, as a class, insisted they could read all five lines! I said alright, counted them off and they read it all with about 75% success.
I was shocked they were able to do that, so I said, "if you can all read it perfectly, no mistakes, I'll call my mentor teacher and let you do it for her." And they read it perfectly, so I pulled out my phone, and called my mentor teacher and told her in a message what my class had done and they said hi. She called me back later, and said how awesome it was that my students were able to do what they did so accurately. She was very excited.
That class runs off of motivation, but more and more it's become intrinsic than extrinsic. They do well in my class because it makes them feel good, they want to succeed for personal reasons. Extrinsic motivation would be if I gave each of my good students candy for doing well. If they sing something as I expect I would give them a reward for a behavior I already expect. One way the student gets a reward for doing something I expected of them, the other way the student isn't rewarded for meeting my expectations, but succeeds and exceeds my expectations because of their desire to do well in my class. Intrinsic motivation can change the dynamics of a class and change attitudes, which is the singular most important thing in everything you do.