When it came to boarding ABC’s Marvel limited series Agent Carter as composer, Christopher Lennertz already had the job before the cameras rolled. More specifically, he served as composer for the Marvel One-Shot: Agent Carter short that was included on the Avengers DVD. The short’s director, Marvel copresident Louis D’Esposito, also helmed Agent Carter’s first episode and served as the series executive producer.

What made Lennertz—a 2006 Emmy nominee for his Supernatural score—the lead contender for the gig was his experience with 1940s-era military music as well as the spy genre sound, respectively accentuated in his scores for the Steven Spielberg World War II videogame Medal of Honor and the 2005 James Bond game From Russia with Love.

“They wanted the music to be smart and lush,” says Lennertz of the direction from the Marvel folk. “(Agent Peggy Carter) isn’t a superhero, but she’s a super spy, and the action music lives in the world of James Bond and Mission: Impossible.”

In exuding Carter’s spirit, Lennertz employed brass indicative of the big band era, specifically French horns for the action scenes, as well as strings. “Peggy is sexy and seductive and with the strings one can slip into espionage and tension,” explains the composer.

At one point, Lennertz’s orchestra numbered 60 members, including a Russian men’s choir for a folk choral piece used in episode five. But one of the most vital instruments that truly captured Carter’s aura was Lennertz’s use of the alto flute. “It feels like a strong woman’s voice, especially as she’s sneaking around” he says of the instrument heard frequently in composer John Barry’s Bond scores. “It also has that spy quality. Peggy is a real ’40s woman—curvy and strong. She can hold a machine gun with the best of them.”

To listen to part of Lennertz’s score for Marvel One-Shot: Agent Carter click play below: