While relatively little of Danckerts' music has survived, his contemporary reputation as a composer and theorist was strong enough for him to be selected as one of the judges at the renowned Vicentino-Lusitano debate, and it is for his participation in this, and his subsequent writings on it and related topics, that he is best known. The judges, including Danckerts, ruled Lusitano the winner. As a result of the debate, Vicentino published his famous treatise "L'antica musica ridotta alla moderna prattica" (1555), and Danckerts replied with his treatise "Sopra una differentia musica sententiata", which however remained unpublished.