The anonymous melody L'homme arme was widely used in 15th and 16th century Europe and served composers as structural and melodic inspiration for their masses. The reason for its enduring popularity remains unclear, but the catchy melody and its stirring, martial theme were clearly appreciated by composers from Dufay to Carissimi. The English vocal ensemble De Profundis continues its Morales project with two very different yet equally outstanding masses based on this melody, alongside the spectacular Magnificat secundi toni.