During the last decade there has been an awakening interest in considering not only formalised learning situations within institutional settings, but also all the various forms of informal musical learning practices outside schools. Informal musical learning outside institutional settings has been shown to contribute to important knowledge and aspects of music education. In this article, I will examine research studies which in different ways focus on formal and informal learning situations and practices or formal and informal ways of learning. I will consider the relationship between music education as praxis (music pedagogy) and as research, and the relationship between these two facets of music education and the surrounding society. I will identify four different ways of using and defining formal and informal learning, respectively, either explicitly or implicitly, each one focusing on different aspects of learning: (i) the situation, (ii) learning style, (iii) ownership, and (iv) intentionality. Formal-informal should not be regarded as a dichotomy, but rather as the two poles of a continuum; in most learning situations, both these aspects of learning are in various degrees present and interacting. Music education researchers, in order to contribute to the attainment of a multiplicity of learning styles and a cultural diversity in music education, need to focus not only on the formal and informal musical learning in Western societies and cultures, but also to include the full global range of musical learning in popular, world and indigenous music in their studies.