The Scottish household in which I grew up and all their (Irish) friends and neighbours always pronounced it Syne, not Zyne, which I've only ever heard from English people. I'm inclined to believe, without being pedantic, that the Scots know how to pronounce their own language whereas the English have no idea what they're singing, and often get it wrong. Just being English and in the majority doesn't make it right, as the Z sound removes the word further from the related word "since", thus clouding the meaning further. Many (most?) English people pronounce "Loch" as "Lock" but that doesn't make it correct or even a sensible alternative, as "Lock" has other meanings.

I hated what Eddie Reader does on that video and can't imagine why the Scottish Parliament chose her with her mangled tune and R&B-style delivery. When she says "Join in!" you can see the blank panic on their faces, and then relief as they realise the tune has changed to a familiar one. There are so many Scottish singers who could have done a decent job of it.

The older (Burns) tune is never going to replace the more familiar one at midnight on Hogmanay, but if you want people to listen to the words, there's a lot to be said for introducing a different tune. The Burns tune is lovely and more reflective, fitting the sentiments of the song.

Marje