<p>Formed by Frank Peterson in the 1990s, the band Gregorian combines the tradition of gregorian chanting from the Middle Ages with modern pop and rock music, and has achieved worldwide fame performing their unique interpretations of international hits. The band has a set of new material for the current tour, which is filled with cool choreography and stage effects including fire, lights and pyrotechnics. During their last visit in Poland, the venues were full to the brim and this year they will make appearances in Wrocław, Toruń and Warsaw!</p>