In 1965, at the age of 43, he began a second career as a singer, with the help of Simone Signoret and her husband Yves Montand, and later with the assistance of the French singer Barbara. Reggiani became one of the most acclaimed performers of French "chanson" and although he was in his 40s, his rugged image made him popular with both younger and older listeners. His best-known songs include "Les loups sont entrés dans Paris" ("The Wolves Have Entered Paris") and "Sarah (La femme qui est dans mon lit)" ("The Woman Who Is in My Bed"), the latter written by Georges Moustaki. He regularly sang songs by Boris Vian ("Le Déserteur", "Arthur où t'as mis le corps", "La Java des bombes atomiques"). His new young fans identified with his left-wing ideals and anti-militarism, most notably during the student revolts in France in 1968. With age he became more and more acclaimed as one of the best interpreters of the "chanson", and also for bringing the poems of Rimbaud, Apollinaire, and Prévert to new audiences.