If you cross paths with Crystal Moselle, be warned, she might make a movie of your life. It’s what the New York-based filmmaker did when she met the shut-in family portrayed in her disturbing 2015 documentary and Sundance Grand Jury Prize Winner “The Wolfpack.” She repeated the feat with a girl skater crew she met on the subway, which turned into the delightful 2018 feature “Skate Kitchen.” The HBO series “Betty” is the spin-off of that film and shares the “Skate Kitchen” cast and well as its combination Instagram Story-meets-surf-style photography. It also features Moselle’s impeccable taste in music, amplified by her longtime collaborator, composer Aska Matsumiya.

Moselle and Matsumiya have been working together for the last 12 years. “It started with us being close friends and not having other resources,” says Matsumiya. Moselle’s process, in practice for a number of brand campaigns and short films, such as “That One Day” for Miu Miu’s Women’s Tales (which also features the Skate Kitchen crew), was to have a song in place first and cut the film around it. She uses this same approach in her own projects, requesting music from Matsumiya ahead of shooting, sometimes even before the script is written.

As Matsumiya describes the work: “I had already created a sound palette with ‘Skate Kitchen,’ which is dreamy and emotional. ‘Betty’ is the edgier, more driven version. I felt it was appropriate for the ‘Betty’ girls to have shoegaze-y, shiny guitar melodies, vulnerable and raw. But the girls only listen to hip-hop. We had to bring those elements in because that’s the rhythm to their everyday life. It has to feel like them. I added lots of trap beats to the score and we named our new genre ‘trap-gaze’.”

“I like the mixture of organic and electronic sounds,” says Moselle. “’Skate Kitchen’ is more sentimental, nostalgic and coming-of-age. ‘Betty’ is more inspiring, more energized. I want it to feel like you’re having a memory that’s beautiful, but you’re sad it has passed — like saudade — the feeling that you’re enjoying the moment so much but knowing it’s going to end. There’s skating on the street; it’s dusk; it’s youth; everything’s perfect, but it’s not going to last forever and that makes you melancholic.”

Having played in bands since she was a teenager, Matsumiya has performed alongside Red Hot Chili Peppers’ Flea, Yeah Yeah Yeahs’ Nick Zinner and Edward Sharp’s Alex Ebert. Her songs also show up twice on the Spike Jonze short, “I’m Here.” A classically trained pianist — she still practices everyday — Matsumiya uses synthesizers, guitars and trap beats in “Betty.” The show’s score is emotive and soothing, sweeping in the slow-motion skating in the street scenes. “We only ever talk about feelings,” says Matsumiya of her conversations with Moselle. “She’ll send me playlists of needle-drops of what she’s feeling in her head for the movie or what she’s listening to while she’s writing.”

The sourced music is also collected ahead of principal photography with Moselle compiling endless playlists. Both classic and current and genre-agnostic. Moselle heard Matsumiya’s daughter, Bebel, working on a song called “Hypnotism” while she was in Los Angeles writing “Betty,” and earmarked it for the show far ahead of finishing the script. Also used: Otha’s “One of the Girls,” which bubbles under a romantic indoor scene between Honeybear (Moonbear) and Ash (Katerina Tannenbaum), and swells over the next shot of Janay (Dede Lovelace) skating by herself.

CAN’s “She Brings the Rain” is the perfect song for the rain scene that closes the premiere episode. Rico Nasty’s “Smack a Bitch” blasts as Indigo (Ajani) skates out of a racist photo shoot, a red floor-length furry Gucci coat flapping in the breeze. Channel Tres’ “Topdown” bumps the party in the park, which is based on Brooklyn’s Soul Summit events, where Moselle went numerous times and Shazamed that particular song for the scene.

“F–kin’ Problems” from A$ap Rocky, Drake, 2 Chainz and Kendrick Lamar and “Haunted” from NYCL KAI, each containing derogatory lyrics, is unexpected for such a female-centric series. “I don’t completely agree with it,” says Moselle. “But the Betty girls listen to this kind of music and I want to stay true to their world and stick with the realism of their experiences. In the last couple of years, I’ve seen a shift with them not wanting to listen to music like that anymore, actually changing the narrative of what young women consume and being vocal about that.”