Improvisation is a commonly recognised marker of flamenco. Since flamenco is a musical practice that was traditionally transmitted aurally and often acquired rather than explicitly taught, there is no widely accepted teaching methodology for the increasing number of participants in this style, and even less guidance on improvisation.The aim of this study is to show what the structural aspects of a flamenco piece are, and which of these aspects are open to improvisation. It also examines how improvisation is conceived of by practitioners, and how it is practised and taught. The observations and findings here are drawn from fieldwork centred on learning the flamenco guitar and consequent ethnographic notes.