That clinches it.

Thanks, Megan. I'm glad it's mah-ree, because the ah sound is a good one for singing.

I'll look into the 'Flowers of Edinburgh,' too.

Hugh, that is interesting about the vocative case. (It doesn't arise in the English words to the song, where Mairi is always is the third person.) I'd never heard of the vocative case before.

Welsh has similar changes, which they call 'nasal mutation.' I've never had a formal class, and I don't understand how it works. I do know that m's can change to either b or v, I forget which.