"Isles of Gletness" is a Scottish waltz found in a manuscript collection now called Tom Buchanan's Scottish Tome with a total of 652 pages containing 1102 tunes. I can't yet run down any background on either Tom Buchanan or his book. There is a North Isle and a South Isle of Gletness east of the Mainland island of Shetland. I learned it from Aly Bain & Phil Cunningham's recording on The Ruby (1997).