Trills & tremolos
Standard trills, with non-microtonal pitches raised by semitones and tones, follow the same rules as when writing for concert flute. As on the flute, trills which make use of the instrument's lowest pitches are impractical, for example from (written) b to c' and c#', c' to c#', and c#' to d#'.
Many microtonal trills are difficult due to the fingering combinations required. Many microtonal trills are available on the Kingma System alto flute, especially those which make use of the instrument's additional keys. As a general rule, microtonal combinations which require the fingers to slide off open holes are impractical at trill speed - for example, quartertone trills in the first two octaves from e flat, e, f, g# and a. On these pitches, timbral trills are more practical and often used instead (see Timbral Trills). The Trill Fingering Charts show the available combinations of trills.
The video below shows a selection of microtonal trills from using the additional levers of the Kingma System bass flute.
Tremolos are possible across the range of the instrument, though notes requiring the smallest numbers of fingers to move are easiest to execute. Avoid tremolos of intervals bigger than a perfect 4th, especially in the top register, as these require difficult embouchure changes and are unreliable.
Some tremolos cannot be realised due to impractical fingering combinations, such as c' to e flat'. Reliable fingerings are provided in the Trill Fingering Charts.
Notation of trills & tremolos
Trills and tremolos can be notated in the standard way, using trill signs and tremolo lines. For clarity when writing microtonal trills, it is recommended that the destination note of a trill is shown in brackets, as shown below. The more traditional method of showing accidentals adjacent to the trill sign may also be used, but this is sometimes prone to confusion, especially when involving microtonal pitches, so an explanation of the conventions used may be required in a glossary.
Standard trills and tremolos
Trills with bracketed notes