Key (wind instrument)

What it means

A key (German Klappe) is a movable lever with a pad that closes or opens a tone hole on a wind instrument. It solves two problems at once: it reaches holes that lie too far apart for the fingers, and it closes holes that would be too large for the finger. Thereby the tone holes can be drilled where acoustics demand it, instead of where the hand can reach. Ring keys and axles connect several keys with one another, so that one finger operates several holes at once.

Musical use

The development of key systems in the nineteenth century fundamentally changed the repertoire. Before, chromatic notes on woodwind instruments were reachable only via cross-fingerings, which sounded different from the main fingerings; remote keys were therefore technically difficult and unequal in sound. With the new mechanisms, among them the Boehm system of the flute, all keys became evenly playable, and composers could write without regard to fingering difficulties. The price was a somewhat unified sound, which is why historical instruments with few keys are again in demand for early music. Brass instruments too temporarily had keys before valves prevailed there.

Performance practice

Press keys only firmly enough that the pad closes tightly; additional pressure bends the mechanism over time and tires the hand. Keep the fingers close over the keys so that the paths stay short. Check the airtightness regularly — leaking pads first show in poor response of the low register and in unclean intonation. Clean the contact surfaces with blotting paper instead of cloths. Have bent axles and loose screws set right by a professional workshop and do not try to bend keys yourself. Store the instrument so that no key stays under pressure.

Bear in mind that key mechanisms produce noises that become audible in quiet passages and especially in recordings: work with calm, short movements and have pads and axles adjusted regularly. With historical instruments with few keys, unequal tone colours belong to the style and should not be evened out. Check the airtightness by playing individual notes quietly; what does not respond in piano is usually leaking.