Abstract: A music teaching aid having a number of reference rings that are positioned so as to have independent rotatable movement on a base member. Depending on the shape of the base member, the reference rings are either substantially coaxial cylindrical sleeves or concentric rings. Each reference ring 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 color coding system such that when segments of the reference rings are aligned in accordance with the predetermined color coding system, corresponding segments of each successive ring will represent the notes of a non-chromatic scale.

Abstract: An electronic information aid displays and calculates the relationships between a series of individual integers which may comprise alphabetical and/or numerical indicia or a series of visual and/or aural indicia or a combination of any one or more of the integers. The aid has a number of reference rings (23a-23g) each of which is independently rotatable but maintained in a predetermined spatial relationship with each other. Each reference ring (23) includes a number of segments each of which displays indicia which corresponds to an integer. When the rings (23a-23g) are rotated so the segments are aligned into an active strip in accordance with a coding system, the segments will display the interrelationship between the integers. Each segment within the active strip can be activated to initiate an aural or a visual response.