The film adopts a documentary format to portray the story of "Emmet Ray," a made-up jazz musician played by Sean Penn. He’s American, and naturally presented as being among the greatest—actually, second only to the very best—a claim supported by numerous segments where supposed authorities shower him with praise and his own musical performances featuring tunes from artists like Django Reinhardt, Stéphane Grapelli, and Duke Ellington. Woody Allen has a history of incorporating this kind of music into his films, and while it’s an imitation tribute, it's not entirely unpleasant. A significant part of what makes it worthwhile is Sean Penn’s performance as the rather unlikeable character whose self-centeredness seemed to be surpassed only by his growing fascination with "Hattie" (Samantha Morton, who delivers a striking portrayal), a quiet and speechless woman who starts relying on him—could he possibly find himself needing her too? The film boasts impressive visuals and meticulous detail, effectively demonstrating the importance of stability in people's lives. I found the constant stream of dialogue to be somewhat overwhelming, leaving little room for pauses, though it does feel believable at times. It’s disappointing that there’s so much exaggeration throughout—how could anyone genuinely be considered the best guitarist?

Source on TMDB