The border pipe is a close cousin of the Highland bagpipe, and commonly confused with the Scottish smallpipe, although it is a quite different and much older instrument. With a conical chanter, three drones in a common stock, tuned as per Highland pipes or Scottish smallpipes, this bagpipe combines the Highland pipe tone with the more manageable key of A, and lower volume, suitable for playing in folk bands and at informal folk sessions. It is driven not by being blown by the player, but instead is supplied with air by a set of stout bellows. This has the advantage that it stops moisture (from the player's breath) condensing on the reeds, with consequent tuning changes. The name comes from Scotland's border country.
Borderpipes and Northumbrians were traditionally popular on either side of the border, giving these two kinds of pipes a parallel history and a common repertoire.
Borderpipes are bellows-blown and feature a common stock with three drones, typically two tenor drones and a bass drone (in this respect, they are similar to the NSP and Scottish smallpipes).
Most Borderpipes are made in the key of A, to enhance their compatibility with other instruments used in Scottish and traditional music; some pipemakers also produce Borderpipes in Bb and G. By the way, should you ever run across a set of Northumbrian half-longs, these are not the same as Northumbrian smallpipes.
The uilleann pipes are distinguished from other forms of bagpipes by their sweet tone and wide range of notes, together with the unique blend of chanter, drones and "regulators" (typically three extra chanter-like pipes, fitted to the mainstock and equiped with keys) which allow for the playing of simple chords and a rhythmic accompaniment.
The modern concert pitch pipes are a relatively recent invention, pioneered by the Taylor brothers, originally of Drogheda, Ireland and later of Philadelphia, USA, in the late nineteenth and early twentieth century.
The pipes are generally equipped with three drones: a) the tenor drone—the highest sounding pipe, b) the baritone drone and c) the bass drone—the lowest sounding pipe, one octave below the bottom note of the chanter.