IMUTUS (Interactive Music Tuition System) is a EU project that aims to develop a practising environment for the recorder, combining new technologies and new approaches for music learning. Automatic analysis and evaluation of student performances play a central role in the student-system interaction. The performance evaluation module identifies typical performance errors, and provides feedback that relates to performance skills, helping the student to improve. The performance evaluation process is based on the knowledge and experience of recorder teachers, obtained via questionnaires, interviews and structured evaluations of recorded student performances. Another important feature of the performance evaluation is that it can be guided by teachers writing the content for IMUTUS by means of annotations.