Selected from the 1578 Obras de M+Ãsica published by blind keyboard master Antonio de Cabez+Ãn's son Hernando, these glosas enrich the vast resource of Renaissance vocal music through variation and elaboration. Extra layers of polyphony and ornament crystallize the tradition of improvisation on pre-existing works, both in the splendour of the sacred, and in chansons and madrigals with more secular emotions. Antonio de Cabez+Ãn's Tientos y Glosados can be heard on Naxos 8.554836, and Glen Wilson's acclaimed recording of his complete Tientos and Variationsis on 8.572475-76.