The operas that Helen Donaldson was best known for appearing in were created by a team who collaborated on how many comic operas?
Helen Donaldson: Helen Donaldson (born 14 March 1968 in Rockhampton, Queensland) is an Australian opera singer best known for her performances of the heroines in Gilbert and Sullivan operas. Gilbert and Sullivan:  The two men collaborated on fourteen comic operas between 1871 and 1896, of which "H.M.S. Pinafore", "The Pirates of Penzance" and "The Mikado" are among the best known.
fourteen