Whistle tones by soundandmusic published on 2010-10-07T10:37:56Z Whistle tones are very quiet sounds created through a very slow stream of air breaking across the embouchure hole. These are hard to produce and even more difficult to stabilise. Sustained pitches are easiest to produce in the instrument’s top register; low register pitches are very difficult. Composers should notate whether they want a stable or fluctuating pitch (fluctuations will be caused by movements in the air stream and will go through the higher partials of the harmonic series). This technique requires a change of embouchure position and air stream speed, so is most reliable when there is a suitable amount of time given for preparation. The precise beginning of the sound is also not always within the player’s control, and a sound coming from nothing is often the most effective method of production.