Bagpipes
Some bagpipes, most importantly the uillean pipes, are capable of overblowing in the sense of jumping to a higher pitch, though most bagpipes are not normally played in this way. Among Highland pipers, the term more often refers to a problem affecting the steadiness and reliability of the pitch and tone caused by an excess of air pressure. When a piper plays, a rhythm is set up between blowing into the blowstick and squeezing the bag. Often, a piper will over-squeeze the bag while still exhaling, causing a pipe to cease to sound or to vary its tone and pitch.
Read more about this topic: Overblowing