“This one has a happy ending,” said Martin Carthy, introducing Limbo, a song about London’s debtors’ prison, “but don’t get used to it.”

Well, he said it. On the whole, this legendary folk singer isn’t renowned for playing jolly, life-affirming numbers.

What Carthy does do – very well – is give audiences a history lesson about the traditional English song, offering modern morality lessons in the process.

This is material where doom and gloom rule and staple subjects include murder, family secrets, illicit love and the hard lives of the working class.

Few singers have as vast a repertoire as Carthy, 69, who famously influenced Bob Dylan and Paul Simon. Yet as a performer he’s modest and self- effacing, with a stage manner that belies his influential status.

I can’t, for instance, think of another artist who would tell his audience he was suffering from too much earwax. I doubt Bono would.

Still, Carthy’s plaintive voice can be an acquired taste, even though his melodic, percussive guitar playing always impresses.

But he shone on Bill Norrie, a tragic tale of secrets, A Stitch In Time – about a battered wife getting revenge on her husband – and The Devil And The Feathery Wife, in which the latter tricks the former by rolling in animal excrement (don’t ask.) Best of all was My Son John – a mother’s devastating lament for her boy killed in the Napoleonic Wars. Carthy brought it right up to date with references to Afghanistan and Iraq, proving the old songs have never been more relevant.