interesting. yes, we have special holiday tones too, but they're variations on the basic set. very cool! enjoy!

a perhaps-interesting aside: we have an "ison", a base drone note that the chanter carrying the line tunes to (traditionally bass register, but when the chanters are a tenor and an alto, well...) the head chanter and I (at the congregation where I was ordained chanter) converged on a pitch halfway between d-flat & d, which annoyed the choir director with perfect pitch. we were super consistent about it though.