In his 25 years in South Africa, he interpreted leading operatic roles, Lieder and oratorio. In Germany and the USA he was a principal performer in oratorio, opera, operetta and Lieder concerts. During the last fifteen years Liebl has performed principal roles in the world premieres of five new operas, The Lost Dauphin, Amarantha, Valley Song, African Songbook, and Words from a Broken String. Among his many former UCT student graduates of note are Abel Moeng (A Standard Bank Young Artist Winner and Finalist in the Cardiff Singer of the World Competition), Fikile Mvinjelwa (A Standard Young Artist Award Winner and First Place Winner of the Boris Christoff Award), Patrick Tikolo (current Head of Voice at the South African e of Music at UCT) and Lionel Mkhwanazi (current Head of Voice at the University of KwaZulu Natal).