||The first of two volumes (the other is RCM42) including all the known music by an important but shadowy mid-fifteenth-century composer. According to the musicologist Reinhard Strohm, Petrus may be synonymous with Pierre Maillart, a Burgundian singer and ecclesiastic. This elegant three-voice Mass will suit solo singers or a small choir: TBarBar. The volume also includes Petrus’ two rondeaux Chelui qui est tant plan de deul and Je vis tous jours en esperance, neither of which survives with its full text. vi + 29 pages. ISMN 979-0-57039-064-9.