Adams was hired by the D'Oyly Carte Opera Company as a chorister in 1951 and soon began to play the small roles of Bill Bobstay in "H.M.S. Pinafore", Samuel in "The Pirates of Penzance", Second Yeoman in "The Yeomen of the Guard", and Antonio in "The Gondoliers", eventually understudying 26 roles. The next season, he took over the principal role of Captain Corcoran in "H.M.S. Pinafore" and substituted for the ailing Alan Styler as Cox in "Cox and Box", the Counsel in "Trial by Jury" and Grosvenor in "Patience". He also appeared once as Old Adam Goodheart in "Ruddigore" and soon began to play the Lieutenant of the Tower in "The Yeomen of the Guard". Adams also began to fill in for the ageing Darrell Fancourt, who missed an increasing number of performances, as the Pirate King in "Pirates", Colonel Calverley in "Patience", the Earl of Mountararat in "Iolanthe", the title role in "The Mikado" and Sir Roderic Murgatroyd in "Ruddigore".