How does a nyckelharpa work?
The chromatic nyckelharpa has three melody strings, which are tuned a1, c1 och g, from the highest to the lowest string. Then "the harp" (as we players call it) has one bass string without keys, which you strike at appropriate occasions, to enforce rhythm and sound. The pitch of this bass string is c (i.e. one octave below melody c1). The particular sound of the chromatic nyckelharpa comes from the12 resonance strings (provided that you tune them). These are below the melody strings (see photo to the left), so you do not touch them with the bow. They will sound anyway, when you hit a corresponding melody note. In other words, there is one resonance string for every half note of the chromatic scale, so if you play the note e, the resonance stringe tuned e will ring, and give the det echo-like sound.
The keyboard
With the fingers of your left hand you press the keys, "knavrarna", to get different notes. Fit into every "knaver" there is a little stick. These sticks are called "löv", which actually means leaf. When you press a "knaver" (see photo below), the stick presses against the melody string to which it belongs. The result of this is that the part of the string that can swing freely is shortened, and you get a higher note.
The range of a chromatic nyckelharpa is about the same as that of a fiddle, from g upp till g3, i. e.three octaves.