As part of the cultural program at the Christmas markets on Old Town Square, a concert of Jakub Jan Ryba's Czech Christmas Mass "Hey Master!" is held every year on Christmas Eve. The performers include the Vox Pragae mixed choir, the Praga Sinfonietta orchestra, and soloists. programme Jakub Jan Ryba — Czech Chritmas mass performers Vox Pragae orchestra Praga Sinfonietta Klára Muknšnáblová soprano Štěpánka Andělová alto Ondřej Benek tenor Martin Matoušek bass Jakub organs Miriam Němcová conductor Übergeordnete Aktionen veranstaltungen Jakub Jan Ryba’s Czech Christmas Mass 13. 12. 2025 — 26. 12. 2025 Zusammenhängende Old Town Square Christmas Market In recent years, the Advent market on Old Town Square has been recognized annually by the world media as one of the most beautiful Christmas destinations in the world, and the markets on Old Town Square bring the atmosphere of a true Czech Christmas to the historic city center.