Will the wedding be indoors or out? If it's indoors, you might want to do a trial run to see how loud the combination is from the audience perspective. If it's a church with a lot of "cathedral" space to soak up the sound, you'd probably be fine. If it's a small chapel, it might be overwhelming. It also might give you some idea of whether you want the piper and drummer to march up the aisle ahead of you or stand in the back. It would be nice not to have your guests sticking their fingers in their ears as you go by!