LOS ANGELES -- Tyler Hilton has some big shoes to fill -- and they're blue and covered in suede.

The singer/songwriter, who has a recurring role on the WB's teen drama "One Tree Hill" as cocky musician Chris Keller, will be starring as a young Elvis Presley in the upcoming Johnny Cash biopic "Walk the Line." "I didn't even know I was going in to audition for it, so it blindsided me a bit," Hilton recalled recently. "They just wanted to audition musicians for the movie and I went in and played a Johnny Cash song. Then they said, 'Do you know any Elvis songs?' which I did because he's one of my favorite musicians from when I was a kid."

So the 21-year-old singer-turned-actor busted out a couple of Presley's tunes and landed a callback for the coveted role of the music legend. "Afterwards, the casting lady said, 'You know, I think we'll have you come back and read some of Elvis' lines,' " Hilton said. "I was like, 'Elvis's lines? That's crazy! I don't know if I can do Elvis. I'm not an Elvis impersonator.' "

Hilton dabbled a bit with acting in high school until he made the choice to focus on his music. Taking the plunge back into acting was not something the singer had anticipated. "I was really nervous about it," Hilton said, admitting he nearly walked away from the role. "But the more I thought about it, I'm such a big Elvis fan, and I would have been bummed if anyone else got this part. I would've been so jealous. So I was happy to take it and I had a good time, too."

The biopic, directed by James Mangold, tracks the early years of country music icon Johnny Cash and his steady climb to fame, with Joaquin Phoenix playing the Man in Black. "It was very easy for me to just be quiet and observe [Joaquin] and just follow him around and be like, 'What's he doing?' " Hilton said. "I kind of got an idea to know what it's like to be a professional, so that was really nice to be around."

Hilton remains modest about his attempt at capturing Presley's larger-than-life persona. "I don't think I ever would have done a good enough job where I would have watched the movie and been like, 'Yes, that is Elvis,' " the singer admitted. "But I do watch it and I'm like, 'That was a noble attempt, young warrior. That was a noble attempt.' "

Reese Witherspoon, who ditched her famous blond locks for her role, will play Cash's longtime love, June Carter. Robert Patrick, Ginnifer Goodwin and singer Shelby Lynne are also featured in the film, set for a November 18 release.

Hilton, who signed a deal with Maverick Records at age 18, released his major-label debut, The Tracks of Tyler Hilton, in November. The first single, "When It Comes," is still gaining momentum at radio, and has consequently delayed the release of the album's second single.

"We've speculated on when it might come out but I think it all depends on how [the single that's out now] is doing and how touring's going," he said. Hilton will perform on the "One Tree Hill" Concert Tour throughout March (see [article id="1498010"]"Gavin DeGraw, Michelle Branch Play For 'Hill' Fans in L.A."[/article]), but don't look for him to decide which one of his tracks he'll release next. "It's tough for me to choose because I like all my songs. That's why I wrote them. It's tough for me to say one's so much better than the other ones."

The singer, who will remain on the road for the rest of the year, said he will largely rely on the crowds' reactions and some online polls to help him determine the next single. "I think we've narrowed it down to a few to see which one it might be, but I'm as excited to find out as anybody else."