Finding the Best Music Teacher
The most important quality in a music teacher is...
the ability to inspire students to practice. Even a teacher who does nothing valuable musically in a lesson will have students who excel if that teacher creates a relationship that makes the student want to work hard in music. Jazz saxophonist Mike McMullen once said, "I have students where we work really hard and they never make much progress, and then some where we basically just hang out in the lesson and they skyrocket...because they're working their butts off in practice. That's where [progress] really happens - in practice!" Any particular student is inspired for their own unique mix of reasons, but here are the main ways a teacher can inspire students to practice.
1 - Ability
A teacher who can really play well might inspire students to practice just by playing well. In extreme cases, some "teachers" never even really teach much - they pretty much play throughout the lesson. That's all some students need to be determined to play like that.
2 - Role Model
Remember your favorite teacher in grade school? You probably remember a lot about what they were like as a person but perhaps almost nothing of what they taught you. The best teachers may be the teachers who, just by presentation, tone, and demeanor, inspire us to achieve more and impress them or be like them. This usually looks like a personal, genuine humility, curiosity, and willingness to be wrong.
3 - Direct Influence
This is purposeful, blatent attempts to guide a student. Depending on the teacher, this can be some mix of encouragement, accountability, incentives, consequences, curriculum choice, lecturing, and the like.
4 - Simplification
Practicing at home can be intimidating when the next step seems confusing or difficult. Students will be more likely to put in good, hard practice when the teacher makes the concepts clearer than the student expects and gives assignments the student has already partially accomplished. That's why, when new concepts are introduced - challenges the student hasn't yet conquered in a previous assignment - a teacher should insure the student accomplishes at least part of it before they leave the lesson. A good teacher is a good de-mystify-er, insuring every student experiences some success in every lesson.