They are a sweet-toned, bellows-blown bagpipe from the North East of England. The chanter (which plays the melody) has a parallel bore and a stopped end. When all the tone holes are closed, the chanter is silent. This gives rise to its distinctive sound where the notes 'pop out like peas out of a pod'. They have 3, 4 or 5 drones held in a single, common stock, but in general only three are used at a time.
The current form of the Northumbrian smallpipes is generally considered to be the work of Robert Reid in the early 19th century. Robert was Newcastle-born but the family moved to North Shields while he was young. This was where he did the majority of his work as a pipemaker, building on the earlier work of John Dunn of Newcastle. Robert's pipes are considered to exhibit fine workmanship and are still sought after and imitated today. Robert's son, James, is credited with developing the chanter to a fully chromatic instrument covering two octaves.
The player holds the bag under the left arm. The bag has three stocks. One, near the top of the bag, just in front of the player's chest accommodates the all the drones. This is the common stock.
Another stock, somewhat below it, holds the blowpipe which brings the air from the bellows.
At the front of the bag is a neck in which the stock for the chanter is mounted.
The drones provide a steady, unchanging accompaniment to the chanter. The drones are driven by single beating reeds and are mounted in a common stock.
They have two parts, the standing part and the sliding part. Moving the sliding part in or out changes the pitch of the drone, allowing the player to tune the drones to harmonise with the chanter. 3 drones are commonly used, the remainder being closed by valves.
The player wears a set of bellows strapped around the lower chest, operated by the right arm. The bellows require a valve to admit air on the outstroke and seal on the instroke.
The blowpipe carries air from the bellows to the bag. It fits in a stock below the drone stock and has a leather flap which acts as a non-return valve
The chanter is the 'melody' pipe and uses a double reed similar to an oboe or bassoon reed. This sits in the stock which provides protection and allows the reed to vibrate freely.
The chanter has 8 tone holes, a parallel (cylindrical) bore and the lower end is closed by a removable stopper. When all the tone holes are closed, such a chanter will be airtight and will not produce any sound.
The majority of chanters also have tone holes operated by keys which are simple levers, spring-loaded to keep the tone holes closed.
Current thinking in the piping community is that the pipes were originally in the key of G, but formerly, pitch was far from standardised and generally lower than today. Historic pipes would appear to be pitched in a range which would lie between modern F and F#. In the recent past there have been attempts to lower the pitch to concert F but the legacy of existing pipes made this difficult. Currently, most players use a pitch around 20 cents sharp of concert F and this is the most common pitch for group playing. There are pipes pitched in G, but these require significant changes in the chanter reed which generally produces a change in tone which many players regard as undesirable.