Technologies such as YouTube, mobile phones and MP3 players are increasingly integrated into secondary school music in the UK. At the same time, the gap between formal and informal music learning is being bridged by the incorporation of students' preferred music into class activities. We conducted an ethnographic study in two secondary schools in London, investigating the roles of technology in the negotiation of musical concepts in music classes. From this, we report some observations on the relation between formal/informal and authorised/unauthorised activities in class, and some specific observations on the role of YouTube, mobile phones and MP3 players in the class context. In the lessons we observed, these technologies functioned as part of a richly multimodal ecosystem of technologies, combining aspects of formal and informal use. This carries implications for how we plan for the use of technology in the delivery of music education.