Hooper's Service is variously named Mr. Hooper's Long, Mr. Hooper's Service to Parsons of Wells flat service, Mr. Hooper's Service of five parts to the Organ, Mr. Hooper's Full Service and Mr. Hooper's Great Service. It survives in three principal sets of choir part-books: those at Pembroke College, Cambridge; Peterhouse, Cambridge; and Durham Cathedral; all date from the 1630s. There is also a tenor part in a post-restoration choir part-book at Ely Cathedral. Given the close relationship between the Durham and Peterhouse sources, the variants between them are remarkably extensive. There are also wide divergences between these two sources and the Pembroke College books. The variants fall into three main categories: accidentals, rhythm and underlay, of which the first is easily the most extensive.