Overtone flute - koncovka
Koncovka (pronounce [kontsovka]) has no finger holes, hence the playing is based on a physical principle of overblowing - different strengths of blow produce different number of nodes in wavelengths, hence different overtones. More tones can be obtained by covering the bottom end (hence the name "koncovka" which means "end flute"). Similar instruments exist in other cultures (Russian kalyuka, Moldavian csilinko, Norwegian seljefloyte). With around 10 different levels of blowing, this flute is suitable for playing in lydian (sharp quart) and mixolydian (podhalanska, flat septime) scales. The instrument is especially suitable for musical improvisation and breath meditations.
I make overtone flutes in A key (small, 39 cm), and in all keys from E (52 cm) to G (large, 86 cm). Most popular keys are C and D.
Download: Playing technique and overtones for a koncovka in C (pdf)