An indispensable symbol of Christmas. J. J. Ryba's most popular composition performed by A. Poláčková, V. Hajnová, P. Nekoranec, J. Šťáva, the En arché chamber choir, the Česká píseň mixed choir, and the Czech Philharmonic Orchestra conducted by J. Bělohlávek. The Czech Christmas Mass, also known as the "Hey, Master" Mass, in Latin Missa solemnis Festis Nativitatis D. J. Ch. acomodata in linguam bohemicam musicam – que redacta per Jac. Joa. Ryba, is a Czech-language church composition by this year's jubilee celebrant Jakub Jan Ryba (1765–1815). Although it is structured in the same way as a Latin musical mass with parts of the ordinary (Kyrie, Gloria, etc.), it is a pastoral play applied to traditional liturgy; the story tells of the annunciation of Christ's birth and the arrival of the shepherds at the manger. The Czech Christmas Mass has a purely pastoral character, set in a Czech environment.