Bagpipes are a class of instruments known as aerophones, producing sound via wind passing through the instrument, such as blowing into a flute or trumpet, only with the bagpipe the air is contained in a resevoir bag that is kept under pressure by the players arm, which allows the instrument to continue playing undisrupted where an instrument such as a trumpet would have breaks while the player pauses to take breaths.
While most of us probably think of Scottland or Ireland when we hear the word bagpipe, they have actually been part of the musical history of many locations of the world dating back to the Middle ages or before.
You can check out http://en.wikipedia.org/wiki/Bagpipes for a more complete history of the bagpipe as well as a gallery of photos of many of the different types of pipes found around the globe today.
These particular photos are of two pipers found at a Civil War reenactment. Each represented Confederate (Southern) soldiers. Ironically, there has never been any documented period evidence of either Scottish or Irish pipes being used during the Civil War in a military context, in spite of the number of immigrant Scots and Irish who fought on both sides during the war. One New York regiment hired a local piping club to play for a parade as they left to go to war in 1861, but after that - nothing. So while it is possible that one or two bagpipes may have found their way into camp, it is much more likely that none of those immigrants - who were likely quite poor and probably had never owned a bagpipe - even knew how to play.
Still, they are good to listen to - in moderation! - if the player actually knows what they are doing. If they do not? Well, let's just say I think a poorly played bagpipe sounds more like torture than music. :)
So don your kilt, brush up on your brogue, and pipe your way over to http://wednesdayabc.blogspot.com/ for more ABC Wednesday fun.