When you look at the Begin Again movie cast on paper, it honestly feels like someone threw names at a dartboard and just rolled with whatever stuck. You’ve got the Queen of Period Dramas (Keira Knightley), a Marvel heavyweight (Mark Ruffalo), the lead singer of Maroon 5 (Adam Levine), and a late-night talk show host (James Corden).
It shouldn't work. On any other set, this would be a disjointed mess. But under the direction of John Carney—the guy who gave us Once—this weird cocktail of talent turned into one of the most soulful, grounded musical dramas of the last two decades.
I remember watching this for the first time and thinking, "Wait, is Keira Knightley actually singing?" She is. And that’s sort of the magic of this movie. It doesn't rely on auto-tune or flashy choreography; it relies on a group of actors who feel like real, messy people trying to figure their lives out in the middle of New York City.
The Heart of the Mess: Mark Ruffalo and Keira Knightley
The movie centers on two people at their absolute lowest. Mark Ruffalo plays Dan Mulligan, a disgraced record executive who looks like he hasn't slept or showered in a week. Honestly, Ruffalo is the king of the "lovable disaster" trope. He brings this frantic, rumpled energy to the role that makes you root for him even when he’s being a total jerk to his business partner, Saul (played by Yasiin Bey, formerly known as Mos Def).
Then you have Gretta James, played by Keira Knightley.
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Knightley’s casting was a bit of a gamble. Before this, she was mostly known for corsets and brooding 18th-century romances. Here, she’s a British songwriter who followed her boyfriend to New York only to be dumped the second he got famous. What makes her performance stick is the vulnerability. She’s not a powerhouse singer—she’s a songwriter. Her voice is thin, raw, and honest.
The chemistry between Dan and Gretta is what really saves the film from becoming a cliché. It’s not a "will-they-won't-they" romance in the traditional sense. It’s a creative soulmate situation. They connect over music, not just physical attraction, which feels way more authentic to the indie spirit Carney was aiming for.
The "Villain" We Can't Help But Listen To
Let’s talk about Adam Levine.
He plays Dave Kohl, Gretta’s ex-boyfriend. Casting a real-life pop star to play a guy who gets corrupted by pop stardom is... well, it’s meta. Levine has admitted in interviews that he basically worked for free on this film because he wanted the experience. While critics at the time were split on his acting chops—some called him stiff—he nails the transition from "indie boyfriend" to "pretentious rock star with a terrible beard."
The scene where he plays the "arena version" of Gretta’s song "Lost Stars" is heartbreaking because you can see the exact moment she realizes they don't see the world the same way anymore. He wants the crowd; she just wants the truth.
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The Supporting Players You Forgot Were There
The Begin Again movie cast is surprisingly deep if you look at the names in the credits.
- Hailee Steinfeld: She plays Violet, Dan’s rebellious teenage daughter. This was right after her breakout in True Grit, and she brings a grounded, cynical edge to the "troubled teen" archetype. The scene where she joins the band to play guitar on a rooftop is probably the most "feel-good" moment in the entire runtime.
- James Corden: Long before he was doing Carpool Karaoke, he was Steve, Gretta’s best friend and a struggling busker. He’s the comic relief, but he also provides the emotional safety net Gretta needs when her life falls apart.
- Catherine Keener: She plays Miriam, Dan’s estranged wife. Keener is one of those actresses who can do more with a look than most people can with a three-page monologue. She grounds the "messy divorce" subplot so it doesn't feel like a distraction.
- CeeLo Green: He shows up as Troublegum, a wildly successful rapper who owes his career to Dan. It’s a small role, but it adds to the texture of the New York music scene the movie portrays.
Why the Casting Worked for SEO and the Soul
From a production standpoint, the casting was brilliant. You had the star power to get people into seats, but the performances were indie enough to keep the critics happy. John Carney actually considered Scarlett Johansson for the role of Gretta originally. While Johansson is a great singer, there’s something about Knightley’s "untrained" quality that makes the guerrilla-style recording sessions feel real.
They actually recorded the music live on the streets of New York. That’s not a studio trick. When you see them under the arch in Washington Square Park or on a random rooftop, the ambient noise of the city is part of the track. The cast had to actually perform in those environments, which is probably why the rapport feels so unscripted.
Common Misconceptions About the Cast
People often ask if the actors actually played their instruments.
Basically, it’s a mix. Knightley learned enough guitar to look convincing, but she’s the first to admit she’s not a pro. Steinfeld actually has a musical career now, but back then, she was mostly acting. The "band" members you see in the background were a mix of professional session musicians and actors, which gave the musical sequences a level of technical credibility you don't usually see in Hollywood movies.
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Another thing: there were rumors of tension between Carney and Knightley after the film was released. Carney made some comments in an interview about Knightley’s "entourage" and her difficulty being "honest" on camera. He later walked those back and apologized, calling himself a "bit of a jerk," but it adds an interesting layer to the film. If there was friction, it might have actually helped the character of Gretta, who is supposed to be guarded and prickly.
Actionable Takeaways for Movie Lovers
If you're revisiting the film or watching it for the first time because of this cast, here’s how to get the most out of it:
- Listen to the Soundtrack First: Seriously, the music stands alone. "Lost Stars" was nominated for an Oscar for a reason. Listen to both the Adam Levine version and the Keira Knightley version to see the narrative arc of the film.
- Watch for the Locations: The movie is a love letter to New York. If you’re ever in the city, you can actually visit the spots like the Bethesda Terrace in Central Park or the Vazac's 7B Horseshoe Bar in the East Village where Dan and Gretta meet.
- Check out John Carney's Other Work: If you like the vibe of this cast, watch Once (2007) and Sing Street (2016). He has a very specific way of using actors who aren't "singers" to tell deeply emotional stories through song.
The Begin Again movie cast shouldn't have been this good. It’s a collection of people from different corners of the industry who came together to make something that feels small, intimate, and surprisingly timeless. It’s about the fact that your life can be a total wreck, but if you find the right people to "record an album" with, you might just find a way to start over.