The purpose of this paper is to construct a comprehensive review of the research literature in the reading of western staff notation. Studies in music perception, music cognition, music education and music neurology are cited. The aim is to establish current knowledge in music-reading acquisition and what is needed for further progress in this field of research. It is argued that the reading of staff notation is an important albeit neglected field in music education research. It is pointed out that research on music-reading skill in adult experts is more advanced than research on music-reading acquisition in childhood. In contrast, music-reading acquisition most often occurs during the childhood years. The paper highlights what music-reading instruction can learn from research and where future research may provide further advancements.