While continuing this path in interpretation with Gaston Litaize, he frequented, for several years, the lessons of musical improvisation by Pierre Cochereau at the International Academy of Nice.
Clerc has given approximately 1000 recitals in more than twenty-three countries, including 24 tours in North America (United States and Canada).
In 1987, he was invited to give two of the opening concerts of the Flentrop great organ in the new auditorium in Taipei.
This international career has led him to perform in renowned festivals such as Bruges, Ravenna, Madrid, Morelia, Saint-Eustache, Paris, Milstatt, Frankfurt, Budapest, Luxembourg, New-Zealand, Buenos Aires and Montevideo.
Clerc has recorded numerous disks devoted to Bach and the German Baroque masters, but considered as one of the specialists in French music of the 19th-20th centuries, he has worked on engraving major works by Franck, Vierne, Dupré, Fleury, Langlais and more recently Cochereau.