This thesis examines how nine teachers in four New Zealand secondary schools are using digital technology in music education in order to gain a greater understanding of how it is used, why it is used and what constraints may exist that hinder implementation. This thesis contends that although there was evidence of considerable use of digital technology in the schools, particularly in composition activities, a range of factors are influencing the choices teachers are making as to how they are using it. Despite the potential digital technology may have to transform classroom activities in music education, usage, in most cases, remains fundamentally conservative and heavily informed by traditional Western art music practices. A multi-site case study approach guided this investigation. Initial descriptive numerical data were gathered from teacher and student questionnaires. Further data came from the semi-structured interviews with teachers and small groups of students in each of the four cases. Findings from the data showed that although the teachers participating in the study had a range of digital technology available to them and they made use of it on a regular basis, a range of factors influenced the choices they made when using it in their classrooms. Amongst this range of factors influencing the choices they made, the most important appeared to be the requirements of an external examination system that is remains informed by Western art music practices and in particular on the cognitive dimensions of analysis, harmony, music history, traditional aural skills and an understanding of music notation and theory. Even though there are specific references to a range of styles and genres in the mandated national curriculum, Western art music practices remain most important to most of the teachers. Findings from the student data showed that the students participating in this study appeared to have a high level of digital literacy and were able to use digital technology in both formal and informal learning situations. A number of the students also discussed and demonstrated their informal music learning skills in performance and composition activities. For these students, contemporary music practices are very important to them and if they do not receive the information they need at school they know how to access it using a range of digital devices in an informal learning environment. This thesis contends that to be a successful music educator in the 21st century, the ability to work with Western art music practices and contemporary music practices is becoming an increasingly important skill.