I couldn't guess how many times I've heard this sung, in sessions more than folk clubs but as much as their meaning is a mystery is the way multitudes merrily join in singing a song they presumably don't understand.
Week after week we joined in with 'The Rybuck Shearer' in Richmond's Black Lion and one night I asked "I'll never open What? Sorbies?" The question was whispered from person to person, each admitting to just muttering something that sounded like everyone else was singing!