Nice movie. Sometimes the actress, Marion Cotillard, sings and sometimes she lip synchs Piaf. She lip synchs the famous songs in French. It actually works pretty well. That way the early Piaf doesn't sound exactly like the famous singer, and the voice is authentic. No one can actually be Piaf.
Her 20 years younger second husband, Théo Sarapo, was strangely missing from the story. In the documentary he was everywhere.
The actress is extremely intense, over the top even, which seems very suitable. The movie ends with the famous song "Non, je ne regrette rien" in Piaf's own voice, one of the great song performances ever.