I’ve done a load of studio work too and it’s amazing what they’ll do, what they can do.
For example they can go in and alter the pitch of any note.
So on my chanter high E is bang-on but low E is a bit sharp and I’m used to ‘shading’ that note to bring it down.
I’ve done gigs where one section of the piece only has low E’s so I can put a piece of tape on that note to make it right in tune. Of course it makes high E really flat! But if there’s no high E’s in that portion who’s to know?
Or one time where I just went ahead and let low E be sharp and did all the normal ornaments on it. They went back and brought the low E’s down to pitch… it’s easy, you just drag the mouse over the note and drag it down to the pitch you want. (Other than that recording, my work isn’t ‘corrected’ pitchwise, because I play in tune. One studio had me hear my raw recording and the same thing run with ‘auto-tune’ and the auto-tune version sounded sterile and plastic-y. They don’t like using auto-tune if they can help it, for that reason.)
I’ve done things where they want the chanter in a different key so I just play the piece in the key it fits best on the pipes and they move it. Or on one thing where I played the piece twice in G and they bumped up the second playing to A.
Recording the drones separately is always best: they can put the drones in wherever they want, or change the pitch of the drones to a different note if they want.
I did one thing where I played The Kesh Jig on the chanter only, then recorded the regs doing hand chords that would have been impossible to do while playing the chanter.
On one movie the composer had me just improvise over and over, and later he edited it to create the thing he wanted. (The edit is pretty obvious)
http://www.youtube.com/watch?v=Us5s01joupg
On one album they had me play anything… I played Silver Spear… and they edited it to fragments that popped in and out at various times (a rap album).
On one album they used the drones as a melody note, sort of, rather than a drone.