“Aside from George Lucas, nobody deserves more credit for the success of ‘Star Wars’ than John Williams,” says Mark Hamill.

It’s a pretty bold statement from the actor who plays Luke Skywalker in five of the eight “Star Wars” movies, including a leading role in “The Last Jedi,” now the biggest-grossing movie of 2017. But then, perhaps more than most actors, Hamill appreciates the role of music in movies.

Hamill’s interest was sparked as a child, first taking note of Carl Stalling’s name as composer on old Warner Bros. cartoons, then Bernard Herrmann’s on the fantasy films of special-effects wizard Ray Harryhausen. “I saw ‘Jason and the Argonauts’ on a double bill with ‘7th Voyage of Sinbad,'” Hamill tells Variety. “I could hum the main-title themes from the time I saw them.

Once he realized that Herrmann was the same composer who had terrified moviegoers with his music for “Psycho,” he was even more wowed. Says Hamill: “What’s ‘Psycho’ without that score? It’s such an impactful and integral part of that whole experience.” As Hamill grew older, and into more of a film buff, he came to appreciate the work of Max Steiner (“King Kong”) and Erich Wolfgang Korngold (“The Adventures of Robin Hood”).

The year 1976 was a pivotal one for Hamill — it was then that he was cast in George Lucas’ sci-fi adventure movie. “‘Jaws’ was the only film of John Williams I knew before he did ‘Star Wars,'” Hamill says. “Obviously, as ‘Johnny’ Williams, he paid his dues in television, but I didn’t come to know that until much later.”

Hamill still has vivid memories of being introduced to Williams’ now iconic score for the first film when producer Gary Kurtz picked him up from his Malibu house en route to a dubbing session. “It was a two-seater sports car with a good sound system,” Hamill remembers. “He put this tape in, and I was absolutely blown away. By the time we reached our destination, I was levitating. I couldn’t believe it. There were tears streaming down my face. I was so overwhelmed, so moved, so delighted. His music was epic. For a movie as modest as ours, his music elevated it to the status of ‘Lawrence of Arabia.'”

Hamill instantly became a fan. He happened to be in London in late 1977 when Williams was recording “Superman” and wangled an invitation to one of the recording sessions. He left thinking the music was so thrilling, “why couldn’t he have saved that for ‘The Empire Strikes Back,’ the next film in the series? I somehow thought of him as ours,” Hamill says with a laugh.

Flash-forward to the new trilogy that began with “The Force Awakens” in 2015. “When we found out that John was going to be the connective tissue,” Hamill says, “the Force was with us on that one. Nobody could step into his shoes.”

Director Rian Johnson invited Hamill to one of Williams’ recording sessions for “The Last Jedi.” “I was just in awe,” Hamill recalls, “to see the entire orchestra, upwards of 100 people, and the way [Williams] communicated with them – he knew all their names! … It’s indescribable, how he elevates every scene. He’s got to understand the emotion of the scene, the dynamics of whatever conflict we’re trying to portray, as deeply as an actor does. In a way, that’s even more complex. As an actor, you’re only one person, one instrument in the orchestra. He’s the entire cast.”