There are three main kinds of bagpipe in Scotland.
Great Highland Bagpipe
A chanter and three drones (two Tenor, 1 Bass), mouth blown via a blowpipe. The chanter produces a scale in the Mixolydian Mode in just intonation. It is a Bb-ish instrument. This is the best known of the bagpipes.
A bellows blown pipe with the same fingering as the Great Highland. Only exist now as modern revivals and therefore in a variety of keys and derived from the Northumbrian except for an open cylindrical bore chanter and Highland fingering.
A bellows driven version of the Great Highland usually in A. A conical bore chanter and a mixolydian scale.
The Scottish Bagpipes can be heard very effectively in a modern Folk setting with the band The Tannahill Weavers.