Note: since I began including this in syllabi (and pointing it out at the beginning of each semester), emails from students have become… slightly… better. The good ones remember this when emailing me. The others can be ignored and referred back to the syllabus. Any other good solutions out there for elevating the tone of student/teacher e-correspondence?
Theory Class Rocks!
Who doesn’t love the same music you do? Your students, probably.

First of all, let’s address the elephant in the room: popular music brought into the classroom by a professor will never be a student favorite. If a timely hit is brought to class to illustrate a point, it will soon enough be out of date. A classroom of students represents a spectrum of tastes, so while you are reaching the Zeppelin fans of the class, you are making the BeyoncĂ© fans roll their eyes.
I think, though, that students appreciate learning from a variety of sources (rock and pop among them) since this illustrates an important concept:
Music theory embraces universal principles, not just irrelevant techniques of long-dead, elite composers.