Harold Hirtz studied violin at the Conservatoire de Strasbourg, and subsequently at the Conservatoire National Supérieur de Paris with Patrice Fontanarosa (violin) and Jean Mouillère (chamber music). He gained orchestral experience in the Orchestre Philharmonique de Strasbourg and the Orchestre Philharmonique de Radio France.
In 2005, he switched to the viola because of the new sound possibilities that instrument offered him. The following year, Hirtz was appointed principal violist of the Philharmonique de Strasbourg and as a teacher at the Conservatoire de Strasbourg. From 2011 to 2012, he also held the post of principal violist of the Basle Symphony Orchestra.
Hirtz joined the Royal Concertgebouw Orchestra in October 2016.
He has performed as a soloist with the Orchestre Philharmonique de Strasbourg in works including Mozart’s Sinfonia concertante, Britten’s Lachrymae, Richard Strauss’s Don Quixote and Béla Bartók’s Viola Concerto. Hirtz has performed chamber music with Patrice Fontanarosa, Marielle Nordmann, Jean Mouillère, Cédric Tiberghien and Jean-Yves Thibaudet.