The Robert ap Huw Manuscript and the Canon of Sixteenth-Century Welsh Harp Music SALLY HARPER The famous book of harp music (Lbl MS Add. 14905), copied by Robert ap Huw in the early seventeenth century, is one of only two extant sources containing notated pieces belonging to the unique Welsh musical tradition of cerdd dant (literally 'the art of the string').1 The manuscript includes thirty-two notated items belonging to four different compositional types; additionally, a list of almost one hundred pieces at the back of the book, also in Robert ap Huw's hand, provides evidence of five more types of composition. Taken together, they appear to provide a comprehensive representation of the types of music played on the harp in late medieval Wales. By comparison with the contents and ordering of many contemporary British lute, keyboard and ensemble sources, Robert ap Huw seems to have drawn on a repertory which is unique and very different in both aesthetic and technique. Furthermore, he appears to have employed a deliberate strategy in selecting the contents of the book, a purpose which accords with his additional inventories. These inventories establish that he also wrote out at least one other manuscript. The harp repertory evident and implicit in Robert's surviving book has a close parallel in the repertory for crwth, an instrument whose status was almost equal to that of the harp among the skilled craftsmen- musicians and their Welsh patrons. Robert's exact motivation for copying this and other books of harp music may never be established. However, the need to write down an orally-transmitted Welsh repertory known to have been in decline from at least the end of the fifteenth century may have been a strong factor, whether for didactic or pedagogical purposes or for purposes of preservation. By 1620, both cerdd dant and the related poetic craft of cerdd dafod ('the art of the tongue') had become subservient to imported English fashions. Each art was to an extent secretive and protected: requirements for craftsmen wishing to enter