A native of Reims, Sébastien Horrer completed his musical studies at the CRR under the tutelage of Dominique Demogeot where he obtained a gold medal in 1987; after that he pursued a cycle of improvement in the class of Elisabeth Fontan at the CRR de Nice, where he unanimously obtained 1st prize for Improvement with congratulations from the jury. In 1990, he was admitted to the Juilliard School in New York and followed with a Bachelor Degree under Nancy Allen. He also benefited during his training from the teachings of Catherine Michel and Frédérique Cambreling. In 1995, he obtained the DE (State Diploma) and a Certificate of Proficiency in Teaching. In 1997, he was named 1st solo harp of the newly created Malaysian Philharmonic Orchestra and participated in the development of a music education programme for young people.
Since his return to France, he has collaborated regularly with two major Parisian groups: the Orchestre de Paris and the Orchestre Philharmonique de Radio France. Sébastien Horrer has been teaching at the CRD de Tarbes since 2007 and at the isdaT since 2016.