A teacher once told me that the reason we repeat ourselves so much is the hope that someday our students will listen. Perhaps this isn't the most creative teaching technique, but anyone who has been teaching for a long time can identify with the sentiment.
Why do we teachers feel this way? One reason is that the most important concepts--the ones that really stick--are often the the most general. Even today, I found myself speaking for an extended length of time, only to realize that what I was saying boiled down to: "Listen to each phrase and play it beautifully". These simple ideas might seem general to the point of absurdity, but they take years to flesh out, and demand constant repetition if they aren't to be lost in the details of day-to-day practice.
As evidence of the effectiveness of general principles, I can associate every influential piano teacher I've had with one, maybe two, guiding ideas. Here's a short list off the top of my head:
- Listen to Yourself
- Create a Beautiful Sound
- Practice Intelligently
I owe a great deal of gratitude to the teachers who mercilessly instilled in me these ideas. The first teacher who got me to really listen to myself did so through a combination of insults, unpleasant language, and threats. It wasn't fun, or even nice, but it changed my playing. It's easy be seduced by complexity--especially when you've been teaching the same thing for several years-- but the most effective teaching often comes from keeping things simple.