I'm sure this has been covered before but there are two sets of words, both attributed to Tannahill, and can be found in R A Smith's Scottish Minstrel, pages 49 and 89., Vol ll, 1821. The version printed above appears on page 89 to the air The Three Carles o Buchanan and I cannot find any one who has sung this tune. Hamish Henderson said it is the air John McDonald, The Singing Molecatcher of Morayshire, Topic 1974, sings but it is not. McDonald sings the McPeakes' melody to The Wild Mountain Thyme!! The version on page 49 says 'Will ye go' and says 'bloomin' heather' instead of 'Highland heather' but uses the tune usually associated with Tannahill's Braes o Balquidder, published in various books during the 19th centuary and found in Norman Buchan's 101 Scottish Songs, 1962. This tune is slight variant on that used by Burns for 'An' I'll kiss ye yet', Johnson's Musical Museum, which is also a slight variant of the very old dance tune called The Braes o Balquhidder. John Hamilton's song 'The Braes o Bowhether, 1796, uses the same tune as Burns did in 1788. I would think Hamilton's lyrics came before Tannahill's so it looks as if Tannahill did a bit of rewriting!