The dialogic idea has a long history and comes in a variety of shapes, sizes and guises. There is Socratic dialogue in which discussion works towards better understanding of where one stands on moral and political issues. And there is John Dewey maintaining that it is through the openness to enquiry and ongoing dialogue that the school can be a place where democratic principles are lived out preparing the child for their future role in developing a participatory democracy. (We see the respective influence of both Socrates and Dewey in ‘Philosophy for Children’ and ‘Enquiry-based Learning’.)
For Paulo Freire the dialogic principle is a means of emancipation achieved through bringing into the light the existential-political concerns of the oppressed as a way to awakening critical consciousness, while for Bakhatin the dialogic is viewed as the root of thought and language. It is this idea that is currently most influential amongst dialogic theories. Dialogic work is above all else about thinking together.
One influential application of the dialogic principle currently in evidence in some schools is directed towards rethinking classroom talk. The work of Robin Alexander  challenges standard methods of instruction – the drilling of facts, emphasis on recall and the imparting of information through cues. In its place is discussion and dialogue. Alexander defines dialogue (teacher-class, teacher-group, teacher-individual or pupil-pupil) as ‘achieving common understanding through structured, cumulative questioning, and discussion which guide and prompt, reduce choices, minimise risk and error, and expedite ‘handover’ of concepts and principles’ . With this the teacher is released from the all too common deadening attempts at classroom interaction through sterile questioning and instead is offered a classroom where all can be engaged in thinking through talking.
The case of music
However, in responding to Alexander’s position there are two matters to note in the case of music. First, if music itself is our primary medium of thought and means of communicating, any consideration of dialogue starts with the idea of musical dialogue. This is what can happen when we improvise music or rehearse music together. Or when a conductor is responding to the responses of the players being led. Call it musical interthinking if you like.
Secondly, in music and the arts we may not be always interested in ‘reducing choices…minimise risk and error’.
And are we wanting to ‘expedite the ‘handover’ of concepts and principles’? Well, certainly there is an important place for this, yes, but here I am moving in a different direction. If you will come with me I want to think about the significance of creating ‘dialogic space’ as a principle of pedagogy for music. Space is of course a metaphor bringing together physical space, time and human relationships. But first some more thoughts about dialogue, each of which can be thought of as a feature of musical dialogue as well as dialogue about music.
‘A dialogue depends upon succeeding utterances and so can never be closed down.’ 
‘Listening well requires a [particular] set of skills, those of closely attending to and interpreting what others say before responding, making sense of their gestures and silences as well as declarations.’ 
‘When humans enter into dialogue there is a new space of meaning that is opened up between them and includes them within it.’ 
The above sentiments can be applied to the processes of making music, to musical utterances, what each other ‘say’ musically as well as what we say about music.
Wegerif speaks of ‘opening, closing, widening and deepening a space’ and this helps to think about the classroom and how it might be as a place where a space can be opened up, nurtured, not closed down or circumscribed by necessity. And unlike Alexander’s moves towards achieving common understandings and consensus we can now move in a different direction, for the opportunity arises for making meaning and the engagement of critical thought which will need some dissensus, not always consensus, different understandings, not always common understandings and some resistance to closure.
In my blog ‘Who will try a dialogic musical gathering’ https://jfin107.wordpress.com/2016/12/08/who-will-try-a-dialogic-musical-gathering/ I provided an example of how we might organise the sharing of responses to musical work without any intention to establish facts about the music or to come to any agreement about its character or how it is.
The February edition of Teachtalkmusic at https://teachtalkmusic.wordpress.com/ is hosting an experiment with a Dialogic Musical Gathering. You are welcome to take part.
 Alexander, R. (2005) Towards dialogic teaching: Rethinking classroom talk. York: Dialogos.
 Ibid, page 30.
 Bakhtin, M. (1981) The dialogic imagination. Austin, Texas: University of Texas Press.
 Sennett, R. (2012) Together: The rituals, pleasure and politics of cooperation, London: Allen Lane.
 Wegerif, R. (2011) Towards a dialogic theory of how children learn to think, Thinking Skills and Creativity 6: 179-190.