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
Paul Burkhard by numerous artists since then, including Alan Breeze, Billy Cotton, Billy Vaughn, Connie Francis, Diana Decker, Eddie Calvert, Eddie Fisher, The Everly Brothers, Harry James, Lys Assia, Ray Anthony & his Orchestra, Russ Morgan & his Orchestra, and many others. Paul Burkhard Paul Burkhard (21 December 1911 in Zürich – 6 September 1977 in Zell) was a Swiss composer. He primarily wrote oratorios, musicals and operettas. The contemporaneous and similarly named Swiss composer Willy Burkhard was no relation to him. Probably his most famous artistic creation was the song "" ("Oh! My Pa-Pa") about the death of a beloved clown-father,