Fretted clavichord
Clavichord in which several keys share a single string course (as opposed to unfretted).
What it means
A fretted clavichord is a clavichord in which several keys share a single string course. The tangents of neighbouring keys strike the same strings at different points and thus divide them into different lengths. This saves strings and space but has a consequence: two keys that share a string cannot be played at the same time.
Musical use
The fretted clavichord was the older form and shaped the instrument from the late Middle Ages into the 18th century. Composers had to shape the voice leading so that no fretted notes arose at once, or distribute the frets carefully. In the 18th century the unfretted clavichord gained ground, in which every key has a course of its own, so that all notes can be freely combined.
The fretted clavichord should be distinguished from the unfretted clavichord and from instruments with other means of tone production: on the harpsichord the strings are plucked, on the fortepiano struck, and on the clavichord struck by a metal tangent and held pressed, which enables Bebung, a slight vibrato.
Performance practice
When you play a fretted clavichord, first check which keys share a course and choose fingering and voice leading accordingly. Play with a very fine, even touch, since the clavichord responds directly to every finger pressure.