"Anne Lorne Gillies and John McCormack also avoid the ue sound when singing in Scots" Though surely neither of these are native Scots speakers. Anne is Scottish yes but a native Gaelic speaker and not from a Scots speaking area. The truth is that pronounciation of Scots differs greatly throughout the Scots speaking areas. There are various dialects and a range of accents within each dialect area. It would be absurd to tell a native Scots speaker that he was pronouncing things wrong. Burns wrote in a range of styles from basically Scottish Standard English to his own dialect of Scots to a more literary Scots. I certainly wouldn't even try to put on an Ayrshire accent when singing Burns. I'd generally just sing more naturally in my own Borders dialect/accent. There are one or two exceptions. In this area we wouldn't pronounce "Scots Wha Hae" like it is pronounced in the song. We'd pronounce it "Scots Whae Hae" but the song is so well known it'd sound strange changing the pronounciation.