The "Rules and the Summa"

"The Regule" of Robertus de Handlo and "The Summa" of Johannes Hanboys are important treatises by Englishmen on the notation of mensural music in the fourteenth century. "The Regule of 1326" provides one of the two most comprehensive views of late ars antiqua notational developments. "The Summa", written around 1375, takes Handlo as a point of departure and incorporates an abbreviated redaction of the "Regule", along with citations of other later English authorities, into an exhaustively systematic survey of ars nova forms and rests.