The genial giant from Pantglas, Bryn Terfel, shows a less amiable side to his character in a special concert to be broadcast on S4C this week.
Bryn will be bringing to life some of the bad boys of the world of opera and he admits these musical villains appeal to him.
"Bad characters are always particularly interesting," says Bryn. "Most rogues require a great deal of imagination to portray them well.
"It can be a problem taking a single song out of its operatic context, but I feel these are strong enough songs to tell a story on their own - they are a short story within a larger plot."
Among the interesting characters he will be portraying are Baron Scarpia, Chief of Police in the opera, Tosca, and another policeman, Javert from the show, Les Misérables. Two other bad boys guaranteed to send shivers down the spine are infamous barber Sweeney Todd, and knife-wielding criminal, Mack the Knife.
Sweeney Todd is one of Bryn's favourite parts. He sang the role of the dastardly barber in Chicago in 2002 and then at London's South Bank in 2007.
"It was one of the highlights and privileges of my career to sing a role by a contemporary composer (Stephen Sondheim) because I don't sing much contemporary music," he says.
Bryn will also introduce us to a character with a rather unusual name, Sportin' Life, from George Gershwin's opera, Porgy and Bess, and Iago from Otello by Verdi.
Keeping Bryn company on stage at Cardiff's St David's Hall will be the Sinfonia Cymru orchestra, and the London Welsh Chorale, under the baton of Gareth Jones.
© 2012 S4C
O Gymru / Made in Wales