I actually found it a little odd that Beethoven was mentioned, since it he was a big fan of equal temperment. His 5th symphony was largely written to explore the idea. In well tempered tunings, you have to play around a central "root note" in order to get a harmonic melody. But in equal temperment, the dissonance is equally spread out across the notes. His 5th symphony was able to take advantage of that in two ways: by being an unusually dissonant symphony to begin with and by jumping all over the place, going from very high to very low, playing the same note repeatedly and yet having it sound the same no matter what key he went to. We're so used to it, however, I doubt most people could really hear the difference.