Incognito (2009) on Netflix

Plot summary

Lucas sang and played guitar in Orly Sud, an underground rock group, during the 1990s. A decade later he stands at the top of the French pop-rock scene, and the songs that carried him there came from a blue notebook he found while searching for photographs of the band. He believes those songs were written by Thomas, Orly Sud's bassist, who had disappeared several years earlier. Thomas comes back, and for three days Lucas must keep his fame hidden. He tries to convince Thomas that he still works as a controller for the RATP and that his house and his Mercedes belong to Francis, a friend who lives off him.