I happened to mention to Pete Clark (renowned Scottish fiddler)that on one of Natalie McMaster's CDs there's a song called "Get me through December" set to the tune of "Niel Gow's Lament for the death of his second wife" - a truly beautiful tune. Pete said very succintly (possibly through gritted teeth!) "That tune doesn't need any words". Similar scenario to Da Slockit Light", I would think.