Generalist teachers undertake music lessons having benefited from few hours of music teacher training. Specialist music teachers can find themselves ill equipped when faced with a full class of diverse students. Both types of teacher mobilise different professional gestures in varying proportions depending on training, experience, identity, and perceived competency. How does the use of professional gesture differ between generalists and specialists? How can music teacher trainers approach professional gesture, opening meaningful dialogue between generalists and specialists, leading to pooled resources and greater self-confidence in areas of music teaching perceived as challenging? Parallel to a project on bodiliness in lessons concerning rhythmical knowledge, a collaboration between a generalist and a specialist music teacher was studied in order to examine their use of pedagogical, didactic and artistic gesture. Both teachers video-recorded three to four lessons, then discussed significant extracts during self-confrontation interviews. The data have been analysed using systematic coding in order to observe and interpret this cooperative situation. Results indicate the complementary natures of musical knowledge, professional knowledge and personal experience, which combined, influence teachers’ use of professional gesture and their music teaching efficacy. An argument is made for supporting cooperative teaching situations that enrich both generalists and specialists.