The teachers demand a consistent standard of sound quality from their students. In every lesson, the teachers are resolute in their insistence that their students produce only high quality sounds (tone quality), the product of consistently correct fundamental technique. Irrespective of the lesson target addressed at a given moment, the teachers’ attention remains focused on the quality of students’ sounds. When students use faulty technique and produce sounds that are below the expected level of quality, teachers immediately identify the problems and require students to repeat the passages until correct technique and beautiful tone are demonstrated in context. The teachers are tenacious about sound quality, continuing to attack the same issues again when they are reproduced. They do not let sound problems persist in their presence.