He had a working relationship with the German organ builder Jürgen Ahrend that began in the 1950s, included the restoration of many organs in Germany and Holland, and culminated in the restoration of Arp Schnitger's largest surviving organ at St. Jacobi, Hamburg.
O meu coração não tem cor | Ecce Cor Meum | Cor Pot | Cor, Blimey! | Nel cor più non mi sento | Exultavit cor nostrum | Cor Caroli |