IF IT ain't broke, don't fix it. That's the mantra of John Carney, writer-director of Oscar-winning romance Once and Begin Again, who remains in a bittersweet musical groove for this effortlessly charming coming-of-age story.
Set in 1985 Dublin, Sing Street revisits the decade of questionable fashion choices, when Frankie told us all to relax and Duran Duran frolicked on sun-kissed beaches with the girls of Rio.
Against this vibrant backdrop, Carney charts the rise of a pop group formed by boys' school misfits, who escape the economic hardships of the era through their infectious, self-penned music.
Life knocks the lads down, but they get back up again, inspiring classmates to rebel against the dictates of their school's disciplinarian headmaster, Brother Baxter (Don Wycherley).
Carney's script delicately touches upon themes of sexual abuse, domestic violence and adultery, counterbalancing the lead characters' exuberance with harsh life lessons that echo perfectly the words of the film's downtrodden heroine: "That's what love is: happy sad."
Laughter and tears come together in sweet harmony. Robert (Aidan Gillen) and his wife Penny (Maria Doyle Kennedy) reluctantly tighten their purse strings, to the chagrin of their children Brendan (Jack Reynor), Ann (Kelly Thornton) and Conor (Ferdia Walsh-Peelo).
Fifteen-year-old Conor transfers to a boys' school, where he falls foul of resident bully Barry (Ian Kenny), but makes one friend in red-haired outcast Darren (Ben Carolan).
Desperate to catch the eye of a local girl called Raphina (Lucy Boynton), Conor forms a band called Sing Street and ropes in some of the local kids including multi-instrumentalist Eamon (Mark McKenna) and duo Larry (Conor Hamilton) and Garry (Karl Rice).
Another classmate, Ngig (Percy Chamburuka), is headhunted because, as Conor innocently observes: "He's bound to play something. He's black."
Buoyed by initial success, Conor and Eamon get their creative juices flowing to pen original songs inspired by The Jam, Spandau Ballet and The Cure. Meanwhile, Conor urgently seeks advice from Brendan about wooing Raphina, whose boyfriend drives around town with Genesis blaring from his stereo.
"No woman can truly love a man who listens to Phil Collins," counsels Brendan.
Sing Street is 106 minutes of fizzing, pop-infused joy that unfolds though the innocent, questioning eyes of sensitive teenager Conor and his brothers in musical arms.
Writer-director Carney conjures lovely scenes like Conor and his siblings dancing around a bedroom to the Hall & Oates classic Maneater, while their parents argue downstairs, or a feel-good dream sequence in a school gymnasium.
Walsh-Peelo anchors the young cast with a performance of touching vulnerability, and his chemistry with on-screen brother Reynor leaves a big lump in the throat.
Songs composed especially for the film by Carney and Gary Clark including the barn-storming Drive It Like You Stole It are perfectly crafted.
Ireland need to recruit them for next year's Eurovision.
SING STREET (12A, 106 mins) Drama/Comedy/Musical/Romance. Ferdia Walsh-Peelo, Lucy Boynton, Jack Reynor, Aidan Gillen, Maria Doyle Kennedy, Kelly Thornton, Ben Carolan, Mark McKenna, Percy Chamburuka, Conor Hamilton, Karl Rice, Ian Kenny, Don Wycherley. Director: John Carney.
RATING: FOUR STARS