A search for "Bagpipe duo" found
Scottish Duo Hamish Moore and Dick Lee recorded two albums, available on Greentrax, in the early 1990s.
Branschke Armstrong Duo, "Antithesis"
A search for "Bagpipe trio" turned up
The Griff Trio
The Great Highland Bagpipe: Solos, Duos, Trios, Quartets & More - Piping Variations (the track ...