| 摘要 |
<p>A device which enables the notes of or fret finger positions for a large number of chords to be determined in a quick and simple manner comprises a cover disc (20) overlying a larger plate (10) and attached thereto for relative rotation by means of a central pin (40). The cover disc (20) is provided with at least one window (15, 16) in the form of a radial slot and has notes of the chromatic scale inscribed in radial sequence adjacent the or each window. The underlying plate (10) has the names of types of chords arranged around its peripheral margin outwardly of the cover disc (20) and the notes constituting these chords or fret finger positions to achieve these chords inscribed in radial sectors (12) inwardly of the names and in positions corresponding to the sequence of notes on the cover disc (20). Thus the plate (10) and the disc (20) can be relatively rotated so as to reveal, in the window (15, 16) the notes of or, respectively, the fret finger positions for any given chord.</p> |
