Still it was necessary to prepare the antiphonary. The library has an ancient and well-preserved Hereford antiphonary of the 13th century. The authentic antiphonary mentioned by the biographer has not as yet been found. In an ancient inventory occurs "Breviarium Antiphonarii", meaning "Extracts from the Antiphonary". In 1902 a committee was appointed to revise the Gradual, Antiphonary etc. The "Vesperale Romanum" is an excerpt of the Antiphonary containing the chants sung at Vespers. Alternative terms for "Antiphonary" are "Antiphonal" or " Antiphony". The "Antiphonary" is written in Latin, but contains strong internal evidence of its Irish origin. In 1570, following the Council of Trent, the Roman Antiphonary was declared universal. His changes in the "Graduale" were few; in the antiphonary, many.