With SING STREET, John Carney goes three for three. Yes, a song can indeed save your life.

First Once. Then Begin Again. Now SING STREET. Filmmaker John Carney seems bent on proving to the world how important music is in all our lives. It certainly was in his own, as this latest and heavily biographical movie so buoyantly demonstrates. His first film used complete "unknowns" as its stars; his second tapped the talents of some very "known quantities" -- Keira Knightley, Mark Ruffalo and others -- and succeeded as well.

With Sing Street, Carney (shown at left) is back to using more "unknowns" again, and the film is every bit as wonderful as his other two. It'll leave you walking on air, feeling delight in both living and listening -- to a score that pays homage to some of the great groups of the 80s while creating original songs that are bouncy and beautiful, graceful and gorgeous -- all on their own. As an added perk, the filmmaker may have jump-started the careers of two young performers we're bound to be seeing much more of in time to come.

Critics, while almost unanimously embracing the film, have mentioned that its story is anything but unique. Starting a band from scratch is not the newest idea to hit music, films or life itself, for that matter. Yet so utterly specific is Mr. Carney as writer and director, and so interesting, funny, moving and real are all the characters he and his actors have created that it is not in the least difficult to imagine you're seeing all this for the first time. And loving every damned minute.

Carney cleverly places us first in the family situation, as we see our hero, Cosmo, a marvelous debut by young actor Ferdia Walsh-Peelo (who might possibly want to consider adapting a "stage" name?). He is shown above, right, with Jack Reynor, who plays his older brother and mentor, Brendan, with such richness, subtlety, range and skill that Reynor comes very close to stealing the movie.

Yes, there have been many movies about starting a band. But the reason for starting this one is certainly a bit different: to impress and then get to know a slightly older girl named Raphina.  As played by Lucy Boynton (above), a veteran of some dozen roles already, it will be this role, I suspect, that puts Ms Boynton firmly on the map. She's beautiful and charismatic, all right, but she also possesses that particular quality of seeming even more so when she seems to trying the least.

Together, Cosmo and Raphina make quite a pair, and the girl's history of troubled parentage and having already another boyfriend just adds to the pair's chemistry and the movie's suspense. Ditto the troubled relationship of Cosmo's own parents (played by Aidan Gillen and Maria Doyle Kennedy) whose economics and intimacy are both spiraling downwards.

Each band member, even those given the least screen time, registers as special and real (that's Mark McKenna, above, right, as the band's smartest and most versatile member) -- and the school bully, too, has something interesting in store from the filmmaker. The songs, as I say, are just lovely. Best of all is the scene in the school gym/auditorium, with the band performing and Cosmo suddenly having a rather special and charmingly low-key-but-spectacular fantasy about everything he wants suddenly coming to fruition.

There are many high points in this wonderful film, but this scene, I think, reaches highest of all. It lets us know from where Mr. Carney is coming, and that, yes, for sure: a song can save your life. (I believe that last phrase was to be the title of Carney's second hit -- until someone had the lesser idea to change it to Begin Again.)

Sing Street, released via The Weinstein Company and running a just-about-perfect 106 minutes, opened to fairly rapturous reviews in NYC and L.A. a couple of weeks back. It opens across country this Friday, April 29. Here in South Florida, you can find it at the Gateway 4 in Ft. Lauderdale, the Regal South Beach in Miami Beach, the Cinemark Palace 20 in Boca Raton, and the Carmike Parisian @ City Place in West Palm Beach. Elsewhere? Just click here and enter your zipcode to learn the theater nearest you.

Blu-ray/DVDebut -- John Carney's music-themed BEGIN AGAIN: Lightning can indeed strike twice!

When Once hit theaters and then home video back in 2007, it seemed a revelation: a low-keyed movie about music and a relationship that never pushed or manipulated but blossomed then grew into a stunning tale that climaxes with as moving and perfect a finale in all movie history. Yes, I know: that's quite a statement, but WTF, it's true! The film's writer/director, John Carney, made a couple of small films since then that never saw release over here. But now comes BEGIN AGAIN, a much bigger-budget movie that hit theaters this past summer via The Weinstein Company and comes to Blu-ray and DVD this week (with an early digital download window that began last week). And what do you know? Lightning has most definitely struck again.

Mr. Carney, shown at left, is not simply conversant with the music business. He seems to understand well how it works, how new music is produced, and the difference between mega-produced mainstream-attracting music and the kind that appeals to a niche crowd. He also, I suspect, know that there is sometimes a way in which to enlarge that niche to the point that it almost looks a little mainstream. For the purposes of movie-making, he also understands how to create characters we like and root for and make them seem real throughout, whatever else happens along the way.

If Begin Again is a bit brighter, happier and star-filled than Once, it is also every bit as interesting, delightful and enchanting. Though sometimes threatening to go off into la-la-land feel-goodness, it keeps its footing and by the end more than earns our good feelings. The movie pairs a seemingly washed-up and alcoholic music producer (the wonderful Mark Ruffalo, below) and a novice singer/songwriter (Keira Knightley, above, at her loveliest and most persuasive, with a good singing voice, too) and lets them slowly find their way toward what they both want and need.

These two actors, along with the characters they play, hold the movie together beautifully. We care about them and their problems, and Carney has the sense and talent to guide his characters through water just deep enough to douse but not drown them. And Knightley and Ruffalo parse every situation and then perform the necessary moments with grace and intelligence. They keep us tightly with them all the way.

Music-wise, Carney has his duo come up with some wonderfully creative ideas that are not necessarily bound to work. But in our current climate of anything-goes-but-most-of-it-won't, these ideas and the way in which they are given life, are simply good enough (sometime a lot more than that) to make it all seem possible. In supporting roles, Mos Def/Yaslin Bey (above, left) as Ruffalo's business partner and Cee Lo Green (below), left) as a popular musician whose career Ruffalo has helped create, provide good negative/positive ballast to various situations.

Adam Levine (below, right) makes his movie debut here, and he's not bad at all as Knightley's shallow boyfriend on  the cusp of becoming a huge music star.

Ditto James Corden (below, right), who is even better as our babe's best friend by way of Blighty.

In the family area, both Catherine Keener and Haley Steinfeld (below, left) shine as, respectively, Ruffalo's ex-wife and daughter. One of the nice surprises Carney has in store along the way involves the marital history of this particular husband and wife

It's hard to explain just how slowly and well the filmmaker and his cast manage to capture our hearts and minds. But they do, they do. And then there's that music -- which I expect you'll want to hear again, as soon as possible after you've finished watching the movie.

I do have two caveats. One has to do with the scene in which Ruffalo hears Knightley play solo guitar and sing but imagines an entire orchestra joining in. We don't need the goofy look of instruments magically starting up like something out of Disney's The Sorcerer's Apprentice. Just the aural sounds would have been enough. Ditto the end credits, during which stupidly feel-good, tie-up-all-the-loose-ends visuals appear to make sure we know everything ends perfectly. (Seems to me that this last one has all the markings of Harvey Weinstein's interference.)

The strong and joyous expression on Ms Knightley's face at the finale is all any intelligent audience needs to feel fine and take away from this wonderful movie. But someone was intent on reaching the dumb audience, too, I guess, thus trying to turn a smart and larger-than-usual niche movie into a possible mainstream bull-dozer. Dumb, indeed.

Begin Again -- via Anchor Bay Entertainment and running 104 minutes.-- makes its Blu-ray/DVDebut tomorrow, October 28. If you missed it in theaters, don't let it get by you now.