Wilbert Friederichs is a singer and choirmaster, songwriter and composer. He has written hundreds of works for choirs, theater groups and comedians, as well as for his own companies Mezzo Macho and Klater. He has written over a dozen full-length works for various companies with Jetse Bremer. Apart from that, she leads project choirs, conducts workshops and takes on musical roles in performances and theater productions of others.