Svilpa
Švilpa - a side-blown flute-like instrument made from tree trunk (willow or aspen) in spring, or ash or maple. It is a short-lived instrument. For the instrument to last longer it had to be made from sturdier wood or metal. It doesn’t have playing holes, so the sound is made by covering or uncovering the ending of the whistle. It is a solo instrument perfect for free improvisations. The sound is low and soft, often affected by noise impurities depending on the blowing technique.
Švilpa was beloved by shepherds who used to whistle improvisational melodies, folk songs and dances.