Bagpipes were once used to call men to war, to encourage them to keep fighting and perhaps to help drown out the sounds of battle.
"Bagpiper Battle of Bazentin Ridge 14-07-1916 IWM Q 4012" by John Warwick Brooke
My Grampa was of Scottish descent, living in Montreal. When WWI started he heard the pipes calling his name, and he joined the Black Watch. He loved the sound of bagpipes and had some military marching records that he liked to listen to on the hi-fi (although Granny would have rather listened to the likes of Bing Crosby).
Canadian Pipers of WWI
Piobaireachd Society (Highland bagpipe) List of Members, Scotland 1905
Piobaireachd: its origin and construction 1915
The story of the bagpipe. With illustrations, a bibliography and list of famous pipers 1911
The Pipes of War: a record of the achivements of pipers of Scottish and overseas regiments during the war, 1914-1918
The Piper's Memorial at Longueval
List of Bagpipe Makers (Wikipedia)
List of Bagpipes
List of Notable Pipers