I think Bagpipe RealTracks could open up a whole hornet's nest of problems.
Because of their "unusual" tuning they are notoriously difficult to accompany.
Matt Finley is correct re it being a diatonic transposing instrument but, to complicate things further, I believe the Bb is more like Bb+ ie slightly sharp, as are some of the other 9 available notes!
I believe the drones are normally A in different octaves (1 Bass, 2 Tenor), I used D and A as being the 1st and 5th of the key used because I found it sounded better.

Some background on the MIDI simulation mentioned in my previous post;
Myself and my musical partner were producing a community hall variety concert which included a Scottish themed segment. One of our numbers was a medley sung as we played acoustic guitars, towards the end of which, a group of Highland dancers came on and began their routine. I made a Bass and Percussion backing track using BIAB and Powertracks (this was before RealBand). About 2/3 through the medley I progammed the pipes to come in quietly then gradually build up to volume. this was the cue for the dancers to take positions then start their routine on the last song. The dance then continued to backing track and guitars for several verses after the vocals finished.
As I said previously the pipes wouldn't stand up to close scrutiny, but in this sonic and visual mix they sounded OK.

Regards
Vintage