The word “soundtrack” doesn’t feel right when describing the music featured on The Leftovers. The show has musical currents running through its DNA, entirely apt for a series that enveloped itself with the full spectrum of human feeling. Music offers the same range of emotion, and even with a haunting score from composer Max Richter, The Leftovers makes spectacular use of hundreds of tunes. But none of these choices are inconsequential to the narrative; in fact, the music itself is an invaluable part of the storytelling. In that regard, it’s almost diminutive to claim that the show’s best moments have great music. They are the show’s best moments because of the great music that was weaved into their fabric.

The Leftovers boasts a range of musical choices from across genres, experimenting with juxtaposition often and to great effect. In the pilot, a bone-chilling instance of this contrast occurs during a scene in which a violent cult, The Guilty Remnant, arrive at a town parade. They’re there to disrupt a commemorative service for those lost during “The Sudden Departure,” a mysterious phenomenon that saw two percent of the world’s population abruptly disappear. The townspeople descend into chaos, driven mad by the sight of the occultists denying their grief. As the two groups clash, “Sweet Love for Planet Earth” by Fuck Buttons plays feverishly, heightening the anxious pandemonium. A sudden musical transition decelerates the pace of the scene: “Piano Sonata in A, D. 959: II. Andantino” by Seymour Lipkin tinkles as the scene descends into slow motion. The town’s police chief Kevin Garvey (Justin Theroux) pulls the angry locals away from each other as the piano lilts. It’s the perfect introduction to music done The Leftovers style.

Kevin listens to music frequently in the show, popping earbuds in when he’s jogging or doing work around the house. The show makes ample use of diegetic sound, giving the viewers a chance to understand the characters in intimate ways. In one unforgettable moment during the second season finale, Kevin performs a karaoke version of “Homeward Bound” by Simon & Garfunkel. Earlier in the season, he blares “Where Is My Mind” by The Pixies while confronting a hard truth: he might be losing it, judging by the near-constant visions he has of former Guilty Remnant leader Patti Levin (Ann Dowd). An instrumental cover of this song plays again throughout the series. The Leftovers is unafraid of putting tracks on repeat and in doing so establish a sound-driven thematic design.

With striking results, The Leftovers sometimes makes unexpected song choices that contrast its sad images with chirpy tunes. The season two opening credits were changed from Richter’s solemn theme to Iris Dement’s bright “Let The Mystery Be,” and that switch sets the tone for the rest of the series. In episode five (and briefly before that, in episode two), “Let Your Love Flow” by The Bellamy Brothers is used in a montage that shows town priest Matt (Christopher Eccleston) caring for his wife, Mary, who was rendered catatonic during The Sudden Departure. The song stops and starts repeatedly, as Matt plays it when he wakes up each morning. By the third play, it’s eery and exhausting as we watch how despondent Matt has grown, going through the motions to care for his unresponsive wife.

The perfectly mismatched tunes continue in season three, culminating in an iconic use of a-ha‘s “Take On Me” during the fourth episode. Engrained in the pop culture blueprint is a shot of Nora (Carrie Coon) sitting in a hotel room alone after sparring with Kevin. Water pours from her eye in one long, unbroken tear as that cheery ’80s synth blasts: “We’re talking away / I don’t know what / I’m to say, I’ll say it anyway.” From that point, the song re-entered the canon and became a bittersweet anthem, breathtakingly reappropriated by The Leftovers in tribute to Kevin and Nora’s difficult romance. Sometimes the unexpected choices are the most evocative, and that’s part of what makes The Leftovers work so well.

This show’s penchant for risk-taking is exemplified in the first episode of season three, which begins with a thematic overture set during the pre-industrial era. Larry Norman’s “I Wish We’d All Been Ready” plays over a wordless sequence in which a fundamentalist community awaits the divine rapture with bated breath. But the day never comes, and the crushing disappointment breeds resentment between a disillusioned husband and faithful wife. The Christian song is a quintessential inclusion in The Leftovers, its lyrics a remorseful lament for those who’ll be “left behind” when the rest are taken for the rapture.

The repurposing of “Va, Pensiero” from Giuseppe Verdi‘s opera Nabucco is one of The Leftovers‘ great triumphs. In season two’s brilliant “International Assassin,” this chorus is repeated throughout, loaning the episode a melodramatic absurdity. It’s difficult to imagine this installment in the series without thinking of the music that defines it; it would be like imagining the show without Theroux or Coon. When the spiritual sequel to this episode aired in season three, episode seven — “The Most Powerful Man in the World (and His Identical Twin Brother)” — the Nabucco refrains returned too. It was yet another reminder of how The Leftovers excels at using music to tie its episodes together.

More than anything, The Leftovers understands how losing loved ones could warp a person’s sense of self. It channels that heartache into its music until the very end. When Kevin and Nora dance to Otis Redding‘s “I’ve Got Dreams To Remember” in the series finale, the show’s masterful musical design reaches a peak that it manages to hit over and over again throughout its three-season run. The Leftovers is a testament to the powers of the cinematic song: music isn’t just a supplement but is sometimes a necessary ingredient for great storytelling.