He considers the representational and dynamic functions of music in the plays, the relationship between music, drama and liturgy, and the performers themselves - who they were, and what they might be expected to do. Related factors necessary to the discovery of how music was used in late medieval drama are also considered, from medieval cosmology and the numerical construction of plays to the age and size of boy actors. Dr Richard Rastall is Reader in Historical Musicology at the University of Leeds, and Dean of the Faculty of Arts.