This chapter investigates the effectiveness of group work during classroom music lessons. 'Ryan's not counting, its 8 beats on C' is a comment made by a music teacher to a group of Year 9 pupils as she rehearsed with them a piece of music on which they were collaborating. The episode exemplifies musical collaboration and the construction of a common knowledge through cumulative talk that also involves the teacher. She is expecting a performance and uses the group as a way of facilitating Ryan's musical development as a performer. Through helping Ryan and assuming the additional role as musical director, the teacher ensures that the group eventually works together to achieve a performance Finney's qualitative notion of 'playfully dialogic' relationships in classroom music can be seen to good effect if one compares the ethical demands he identifies in music education to Littleton and Mercer's application of socio-cultural discourse analysis.