| 摘要 |
<p>A device of the type of a slide rule and adapted to indicate and teach musical data and, in particular, the chords, their construction and relationship, and their easy transposition from one key to another, This device includes a base member having a rectilinear groove in the front face, a ruler slidable in this groove, a chromatic scale marked on the front face of the ruler, diatonic scales of the major and its direct minor modes marked along the opposite edges respectively of the groove, and chord indicators on the front face of the base member and bearing coded identification of their interval, their localizations, their qualification, their component thirds and their distinctive notes. In a particular embodiment, the indicators indicate the major common chords and their derivatives and the pointers indicate the modal and tonal notes of each chord when involved.</p> |
