A priority area identified by the Department of Education (England) and the Economic Social and Research Council is the development of teachers, especially in primary music education where the limited opportunities for training offered by teacher training providers have raised concerns. This paper reports on an evaluation of a collaborative partnership training of non-specialist teachers, using a Kodály-inspired pedagogy to teach music in a classroom setting. Participants included 54 teachers (and 1492 pupils, aged 5-6), selected from 55 schools, as part of a large randomised control trial (RCT) in the north of England. This paper presents findings from a qualitative study that was conducted alongside the RCT, but which was not part of the RCT itself or the RCT's implementation and process evaluation. Results from the study, which include a pre-post survey of teachers, focus group interviews and reflective journals, suggest promising effects on teachers' pedagogical skills, their self-efficacy and competence, and children's self-confidence and disposition for learning.