The Kingma System allows for reliable quartertones across the majority of the instrument's range. Exact quartertones are not available below written d', due to the already demanding role for the right hand little finger (see Range). Small pitch changes may be possible on the lowest notes using pitch bends, though flexibility is greatly reduced with these low notes and accuracy is not guaranteed. Quartertones retain the sound quality of the standard pitches, and the additional venting that the Kingma System provides allows for smaller intervals, such as eighth tones, to be produced through a series of modified fingerings. Due to the complexity of microtonal fingerings, and the size of the instrument's keys, transitions between notes can sometimes be slow, and care is required when writing fast passages.

For accurate intonation of small microtonal intervals (for example, in spectral music where a composer may require a particular frequency of pitch) it can be useful to provide the performer with a recorded reference pitch.

One octave quartertone scale from written d'

Microtonal fingerings become more difficult to reach and less reliable towards the very top of the instrument’s range. This is due to the general tendency of alto flutes to become sharp in the upper register, and modified fingerings are sometimes required to stabilise the pitch.

High register quartertone movement

Agility of quartertones

Standard flute playing involves the player raising and lowering the fingers on prescribed keys (usually one key for each finger). The quartertone fingerings of the Kingma System rely on the central open holes of the keys being uncovered while the outer ring of the key is depressed. This requires a forwards and backwards sliding movement which is less agile than the usual lifting/pressing motion. Where a key is not operated directly by the fingers, a lever facilitates this action. This means that some fingerings require a considerable change of hand position, which can further limit flexibility. The fingering system is logical, relying on the sharpening of each standard note to raise it to the quartertone above.

Microtonal fingerings require a change of hand positions from the standard flute playing positions, often sliding sideways to uncover the open holes. This means that fast microtonal movement requires considerable physical movement. Ordinarily note changes require the fingers to move up and down, with no other hand movements. This is obviously considerably quicker than a movement which involves the whole hand.

Sliding movement from fully closed to half holed keys to create quartertones

Chromatic movement in low register

Notation of microtones

As previously mentioned, the fingering system for the Kingma System alto flute relies on sharpening standard pitches in order to create higher microtones. This means that for the purposes of quick reading, quartertone sharps are easier for the player to execute. However, in a piece of music, it is often best to follow theoretical convention with the use of sharps and flats, and to notate them as shown below:

Quartertone notation - sharps

Quartertone notation - sharps

Quartertones may also be indicated using arrows on the accidentals before each note, though it must be made clear that these are in fact quartertones rather than pitch bends. Some composers prefer to use this system for pitch increments of less than a quartertone, so it is advised to make this clear in a glossary. For smaller pitch increments, precise frequencies may be given (eg +27 cents etc).

Quartertone notation - sharps

Quartertone notation - sharps

Quartertone notation - sharps

For smaller pitch increments, precise frequencies may be given (eg +27 cents etc).

Microtonal notation - cents