In February 2001, Andrew completed a set of 5 pieces for the Kingma System quarter-tone alto flute. The music, which comprises of 30 minutes, made a special feature of the newly commissioned Kingma System Alto Flute.
The instrument is capable of ¼-tones throughout the majority of its range. The instrument has 7 extra keys making it a 29-key, open-holed alto flute, with an open-key system for the A, B, C, D, and E keys(transposed D, E, F, G and A) is available with a B-foot joint, (sounding low F#).
Since the instrument was newly designed, Andrew felt conscious that composers should strive to build the available repertoire.
History of the Kingma System Quarter-tone Alto Flute...
In the year 2000, Eva Kingma made & patented the Kingma System®
open-holed Alto Flute. The result of this effort led to the development
of a line of instruments with more flexible intonation and tuning
possibilities. Following the development of the Key-on-key
mechanism the patented Kingma System series of open-holed ¼-tone Alto, Bass and Contrabass flutes were created.