The 12th Musica Sacromontana Festival (2017) saw the contemporary premiere of another work by J�zef Zeidler, the spiritual patron of this event. The Mass in D major (just like the monumental Mass ex D) has been preserved in the collections of Die Bayerische Staatsbibliothek in Munich. The Mass in D major seems to be a more personal and natural work, where simplicity gains the features of conscious artistry. The music is maximally organized, both in the construction of individual phrases and larger formal entities. The MUSICA SACROMONTANA Festival is meant to continue the intentions of the Oratory of Saint Philip Neri, who wanted to evangelize through the broadly understood propagation of culture. It is thanks to their efforts that in the 17th century a great ensemble was created there, and the greatest composers, including Palestrina, came to Gostyn. Many of them wrote pieces on commission of the Congregation; fathers also filled the library with copies of works of the greatest masters.