The overall purpose of this article is to provide a convenient summary of empirical research on improvisation in general music education and thereby provide guidance to researchers and practitioners, using a systematic, narrative-review approach. By analysing 20 music education research articles, published from 2000-2015 in peer-reviewed journals, we firstly provide an overview of the key features and knowledge of existing research. Secondly we identify how improvisation has been characterized, conceptually before, thirdly, describing the implications of the literature for improvisation in practice. Our article reveals that improvisation tends to be an overlooked activity both in music education contexts and in music education research. Broadly speaking, music education research tends to characterise improvisation within two conceptual frameworks, which have different implications for implementation; 'structured', teacher-directed improvisation and 'free', child-directed improvisation. We conclude by arguing that music educational research on improvisation is an underdeveloped field and outline a number of questions to be addressed in future research.