This six-volume series of masses brings to light for the first time the work of the highly accomplished yet little-known Northern Italian composer Ippolito Baccusi (d. 1608 or 1609), maestro di cappella in Spilimbergo, Venice, Mantua, and Verona; friend of Giaches de Wert; and teacher of Lodovico Zacconi, who ranked him among the finest contrapuntists of the time. This edition includes an updated biography of Baccusi that draws upon archival documentation to present new details about his life and career. The four masses of the Missarum cum quinque, sex, et octo vocibus liber secundus (1585) are all based on madrigals: “Vestiva i colli” by Giovanni Pierluigi da Palestrina (used as the model for both the Missa Sancti Stephani and Missa vestiva i colli, though with the musical themes of the madrigal reordered in the former), “Dolce fiammella” by Giovanni Maria Nanino, and “Altro non è ’l mio amor” by Philippe Verdelot. While the Missa Sancti Stephani was probably composed between 1574 and 1580, during Baccusi’s tenure as maestro di cappella at the Venetian convent of Santo Stefano, the remaining three masses likely date from after 1580, when Baccusi became maestro at the cathedral in Mantua.