In Seventeenth-Century Portuguese Keyboard Repertoire, one of its most important testimonies is Padre Manuel Rodrigues Coelho´s Flores de Música para o instrumento de tecla e harpa, published in 1620 in Lisbon, and the organ music manuscripts of Braga and Oporto, Public Libraries. In the case of Oporto it deserves mention the music manuscript Livro de obras de órgão (1695) composed by Frei Roque da Conceição. These music sources have been studied by various scholars, among them Santiago Kastner, Gerhard Doderer and Klaus Speer. There are also a few cases of Seventeenth-Century four-part writing in open-score format, which should as well be applied to the keyboard. I am referring to Music Manuscript 52 (P-Cug MM 52) of the Coimbra University Library (BGUC) which contains in its last part a group of pieces in open-score of unknown authorship, which deserve our attention. In an article written in 1983 – New Sources for the Study of the Portuguese Seventeenth-Century Consort Music - Rui Vieira Nery, besides underlining the importance of Frei Teotónio da Cruz´s († 1653) modos concertados for Consort included in MM 52, also identified the four-part pieces in open-score that I am referring to, which have not yet been transcribed, edited and studied. Given that these pieces should also be included in the keyboard repertoire, as the respective transcriptions testify, my purpose in this paper is to discuss its formal and stylistic traits in the context of the Seventeenth-Century Portuguese Keyboard Tento and Verso.