The bag gives the player a reservoir of air which allows continuous playing. In the hands of a skilled piper the drones give a continuous unwavering accompaniment to the chanter which can execute long melodies, without the player requiring a breathing space.
Pipes such as the typical scottish bagpipes are quite loud and are intended to be played outdoors. They are often called Great Pipes and in partiticular, the scottish bagpipes are now frequently referred to as Great Highland Bagpipes (GHB). Along side this tradition there have been a quieter, indoor pipes which were often referred to as smallpipes. The first Northumbrian smallpipes had a simple chanter with eight tone-holes and no keys. It was about eight inches (20 cm) long and the spacing of the fingerholes was just about as close as could be managed. The bore of the chanter is parallel which gives smallpipes a very different sound to the skirl of their raucous neighbours.
They are bellows blown, which means that the passing over the reeds is dry and so the reeds can be finer than in a mouth blown pipe. The drones may be used in a wide variety of combinations, so that tunes may be played in various keys. However, the feature which sets the Northumbrian Smallpipes in a league of its own is the fact that the end of the chanter is closed. This means that when all the tone holes are closed the chanter falls silent. Players of the Uillean pipes can achieve a similar effect by stopping the end of the chanter on their leg, but this closed fingering is the starting point for Northumbrian Smallpipes and could be said to be the natural or proper way to play the instrument.