While bagpipes are most strongly associated with Scotland, similar instruments have existed across Europe, the Middle East, and North Africa for millennia. The basic anatomy of a bagpipe includes a blowpipe for air, a bag (reservoir), a chanter (which plays the melody), and drones (which provide a constant pitch). The Scottish Great Highland Bagpipe is unique for its power and the use of three drones (two tenor, one bass). The player squeezes the bag with their arm to maintain a constant air pressure, allowing the sound to be continuous, even when the player stops blowing to take a breath. Because the sound is constant, bagpipe music uses 'gracing' (rapid extra notes) to separate melody notes of the same pitch. Historically, the bagpipes were used as instruments of war, intended to inspire Highland troops and intimidate enemies on the battlefield, leading to their classification as a 'weapon of war' in some historical British laws.