Klaus Mertens and consistency, Klaus Mertens sang in every piece that required a bass soloist, 190 in all." He is also involved in the project Dieterich Buxtehude – Opera Omnia of the same ensemble to record the complete works of Dieterich Buxtehude, begun in 2005. As a singer of lieder, he has interpreted songs of Claudio Monteverdi, Antonio Caldara, Wolfgang Amadeus Mozart and Franz Schubert among others. He has performed the title roles of the romantic oratorios "Elijah" and "St. Paul" by Mendelssohn and, as music of the 20th century, Paul Hindemith's "Requiem" and Igor Stravinsky's "Oedipus rex". In the classical repertory
Church of St. Peter and St. Paul, Vilnius 1766 and only fragments survive to the present day. With the loss of the altar, imagery of Saint Paul diminished significantly within the church. The altar as such was not replaced. Instead, Kazimierz Jelski sculpted four prophets (Daniel, Jeremiah, Isaiah and Elijah) while Franciszek Smuglewicz painted the large central painting depicting the emotional final parting of Saint Peter and Paul. Four other paintings hang in the choir: another painting by Smuglewicz depicting Archangel Michael, painting of Saint Mary Magdalene of Pazzi, a formal portrait of founder Michał Kazimierz Pac, and a painting of crucified Jesus. This painting depicts a solar