They use a song from Edith Piaf, though I am not sure if that was a nod to Marion Cotillard, who played her in La Vie En Rose.
Cotillard doesn’t lift this performance to the level of the ones she gave in La Vie en Rose or Nine , but she does sufficiently well given her character’s purpose in the film.
Ms. Cotillard, her most famous movie role evoked by occasional eruptions of Édith Piaf on the “La Vie en Rose” soundtrack, is the film’s principal enigma and its chief signifier of emotion.
The other big asset in that regard is DiCaprio, who invests his character with pain and regret (not for nothing is Edith Piaf’s “No, I Regret Nothing” the theme of “Inception,” and sorry to go all nuts on the parentheses but, parenthetically, yes, Piaf is the character Cotillard played in “La Vie en Rose,” so that adds an additional layer of is-it-a-dream-or-is-it-real?).
DiCaprio delivers, as does Marion Cotillard (La Vie en Rose, Public Enemies).