Abstract: An electric guitar type stringed musical instrument having an elongated fingerboard, an upper headpiece and nut and a lower tailpiece and bridge, with a first set of primary frets placed in regular sequence along the fingerboard from its upper end to its lower end and a set of secondary frets each placed intermediate a pair of primary frets along the fingerboard. Each secondary fret is in off-set diagonal orientation with respect to the primary frets and is so placed between primary frets that upon tapping of a string of the instrument at a point below a secondary fret with depression of the string to contact the secondary fret and a lower primary fret two harmonically resolved, bi-directional musical notes are generated through the string. One of such notes is related to the length of the portion of the string between the lower primary fret and the bridge of the instrument and is picked up by a pickup head of a lower magnetic pickup assembly.