A music learning aid, comprising: a first rotatable circular substrate having a radius (R1) comprising an in-use first visible circular scale displayed on the first substrate, the visible display comprising a plurality of indicia for indicating corresponding musical notes such that the musical notes indicated in the visible display scale ascend in frequency in a clock-wise or anti-clockwise direction; a second circular substrate having a radius (R3), the second substrate being arranged to be substantially concentric and rotatable relative to the first substrate by the fastening arrangement to enable the second substrate to rotate relative to the first substrates, the second substrate comprising a polygon with vertices of the polygon being located along the circumference of the second substrate, the second substrate comprising respective indicia corresponding to each of the vertices for indicating a respective musical mode selected from a set of a plurality of musical modes.