Thus fingering is always critical, even when playing a simple slow tune - if you miss, or don't completely cover a fingerhole, all sorts of nasty sounds result. Unlike most other wind instruments, fingering is everything when piping. The bagpiper, confined to playing with a steady airflow and without direct control of the reed, has only the fingers to provide character and definition to the music. This demanding fingering takes place against the sound of the three drone pipes, each equipped with a reed, that each produce a steady single continuous note. This must become automatic because if the player has to think about it concentration on the fingering will likely suffer.
Steady pressure is also necessary to correctly tune the drones prior to play.
The first thing to give out for many people are the mouth muscles which maintain a seal around the blowpipe. Then there's the arm - again not usually so much of a problem, but the squeezing is tiring until one gets in shape. Again, all of these factors conspire against the novice to make playing a full set of pipes just about impossible. A practice chanter is an instrument in its own right, but its primary purpose is to provide a bridge to playing the Highland bagpipe. Later on it provides a convenient way to practice new tunes, complex fingerings, and so on, especially at times when practicing on a full pipe is impractical.