 Soon afterwards, he assumed the additional roles of Frederic in "The Pirates of Penzance", Prince Hilarion in "Princess Ida", Nanki-Poo in "The Mikado", and occasionally Marco and later, Luiz, in "The Gondoliers".When Thomas Round left the company in 1964, Potter also took over the role of the Defendant in "Trial by Jury" and the Duke of Dunstable in "Patience".He also sang Richard Dauntless in "Ruddigore", beginning when that opera was revived in 1967.