In the same year, Lays politely refused Napoleon's invitation to join him on his expedition to Egypt. Nevertheless, the pair remained on friendly terms and between 1801 and 1802, Lays – who had often performed in Josephine's salons – became chief singer of the Chapel Napoleon had established at the Tuileries under the directorship of Giovanni Paisiello. As such, three years later, on 2 December 1804, Lays was the lead soloist in the music accompanying Napoleon's coronation as emperor. The ensuing celebrations culminated at the Hôtel de Ville on 16 December with Lays and Chéron singing the cantata "Trasibule", specially written for the occasion by Henri-Montan Berton. In 1810, when Napoleon divorced Josephine and entered into a second marriage with the Austrian Archduchess Marie Louise, Lays was the obvious choice to perform at the wedding ceremony. Meanwhile, his stage activity continued unabated, and in 1807 he was also appointed to serve on the Opéra jury in charge of evaluating new works to be staged. Other members of the jury came and went, but Lays remained in office continuously until 1815.