When I was a student I spent some time at the school’s clavichord … but eventually gave it up, I just couldn’t make musical sounds.
Now, after these studies in intonation, I think I could play it better. Follows the one secret key to playing a clavichord:
Background 1: like a guitar, a lute, a theorbo, the clavichord can only tune in one direction: sharp.
Background 2: most instrumental music follows vocal music: we tune the notes that are and should be low, and just follow ‘tonal center’ for those notes that are and should be tuned high.
HENCE(!) on a clavichord you must reverse your ideas: the tonic, dominant, subdominant notes in a tonal area are the ones that need the extra pressure on the keys; play the thirds of a major triad very lightly. For a minor triad, of course, play the third with pressure and the fifth and root lightly.