A neume is a basic unit of musical notation used in Gregorian chant and other early forms of Western music. It represents a single pitch or a group of pitches and is typically written above the text of the chant. Neumes were developed in the 9th century and served as a way to indicate the melodic contour of the music, guiding singers in performance. Unlike modern musical notation, neumes do not specify exact pitch or rhythm. Instead, they provide a visual cue for singers, allowing them to interpret the music based on their understanding of the chant. This system laid the groundwork for the development of more precise notation systems, such as staff notation.