A music teaching aid (10) which comprises a base member having a surface on which a number of reference rings (13) are positioned so as to have independent rotatable movement on the base member. Depending on the shape of the base member, the reference rings (13) are either substantially coaxial cylindrical sleeves or concentric rings. Each reference ring (13) has an outside surface which is divided into segments each of which displays indicia representing a note of the chromatic scale and which is identifiable by a predetermined colour coding system such that when segments of the reference rings (13) are aligned in accordance with the predetermined colour coding system, corresponding segments of each successive ring will represent the notes of a non-chromatic scale.