My first reply vanished

My browser can't do anything with .m3u files, so I'll guess. If it's "Goodnight and [joy/God] be with you all", it's a Scottish song whose tune is known from the early 17th century (Skene MS) and for which words were first published by Walter Scott. There are many 19th century Scottish adaptations, and it was popularized in the Irish music world by some group of the 1970s as "The Parting Glass" (with words not very different from Scott's and the tune identical to the Scottish one as sung around 1800).