Secondary school music curricula often alienate young people because of the disjuncture between their experiences of music outside and inside school (Spruce and Matthews, 2012). Music also continues having to justify its place in many secondary schools (Philpott, 2012). Offering ideas to expand music educational thinking and increase its social relevance, this research explores two secondary mainstream-special school integrative musical projects using the theoretical framework of ‘musicking’ (Small, 1998), which asserts the centrality of relationships in any form of musical performance. Using two case studies, the relationships between teacher and pupil participants are explored. Small makes no mention of musicking in the context of children with special educational needs, and this study extends his ideas by developing the notion of an inclusive form of musicking in secondary music education, achieved through the musical integration of mainstream pupils with their special school peers whose verbal communication is severely limited. The self-efficacy of participating teachers is considered an important contributing factor to the projects’ perceived success, enhancing or limiting the likelihood of their application in other secondary educational contexts. Possible ways of augmenting the self-efficacy of teachers from both settings are offered, together with suggestions for future research in this field.