Abstract: The invention is a musical aid used to simplify the comprehension of chord inversion structure and enable the composer to more readily visualize the keyboard location and fingering of chords and their inversions used in a composition, the device having a frontal panel display of the scale tones of a particular key signature and a sliding member behind the panel which is provided with numbered, pivotal indicators to select a triad orderd in the root or an inverted position from the Scale tones on the panel, the invention including a rotatable disc on the sliding member having selectively exposeable chords displayed on the periphery thereof naming the triads and their inversions occuring in the key signature of the panel.