When lost souls meet and music is made, there is bound to be magic. Gretta (Keira Knightley) finds herself lost when her boyfriend, rising singer-star Dave (Adam Levine), falls to the temptations of success. Disgraced record-label producer Dan (Mark Ruffalo) is suffering with the pressure of raising a teenage daughter (Hailee Steinfeld) with his ex-wife (Catherine Keener). By chance, Dan hears Gretta perform a song she wrote in a local bar. Enlivened by witnessing such raw talent, he is determined to help produce her album with all its heart and soul – live on the streets and full of the sounds of the city. Directed by John Carney (famous for his soulful production of “Once”), “Begin Again” also stars James Corden and CeeLo Green.

This movie delivers. Not only do the actors harmonize perfectly on screen (particularly Knightley and Ruffalo), but the music breathes and weaves life into a fearless storyline. Refreshing is this true overnight urban gem, after years of cinema glamorizing those living off the cream. In fact, as Carney says himself in a bonus reel, the movie also acts as a love letter to New York.

Knightley’s exceptional singing talent transforms her songs. Mastering rarity and vulnerability, she pits a worthy stance against Levine’s infamous voice; “Lost Stars,” “A Step You Can’t Take Back,” and “Tell Me If You Wanna Go Home” are just a few of her songs that went viral on YouTube after the movie’s release.

But perhaps the greatest reason to watch “Begin Again” is for the heart. You’ll be on your feet, swaying to the beat, cheering on breathlessly human characters. Lives mend before your eyes, only you feel it in yourself as well, all captured effortlessly in the sounds and sweeps of the city and its beautiful lost stars.

This film is rated R.