Born in Toledo, Diego Ortiz published the Trattado de Glosas in Rome in 1553. At that time he was living in Naples in the service of Ferdinand Álvarez de Toledo, Duke of Alba and Viceroy of Naples. This region was deeply influenced by Spain. His treatise, published simultaneously in Spanish and Italian, is first and foremost a precious source for the art of Spanish instrumental performance. The second book of the Trattado de Glosas is performed here in its entirety, with Bruno Cocset and Guido Balestracci alternating in the Recercadas. As a counterpoint to this corpus mingling inventiveness and virtuosity, the programme includes short pieces by composers emblematic of the Golden Century of Spain, contemporaries of Ortiz: Antonio de Cabezón, Luis de Milán and Tomás Luis de Victoria. The process of reinterpreting this repertory is closely linked to the rediscovery of instruments that have disappeared and been recreated for the occasion: based on information gleaned from the luthiers Gasparo da Salò and Domenico Russo, the paintings of the Spanish master El Greco, the engravings in Ganassi’s treatise Regola rubertina and the few remaining – and alas ‘restored’ – instruments from the period, five viols have been specially made by the luthier Charles Riché.