The teenager wowed the judges and audience on Saturday night's opening audition episode, following a performance of 'Make You Feel My Love' for the new look panel.
New judge David Walliams told him after the audition: "I think when you tackle a song like that, it’s not just your voice it’s the way you make us believe you’ve lived every line of that song. I was completely blown away."
Speaking after the show aired at the weekend, Sam explained this week why he decided to apply for Britain's Got Talent rather than its sister show The X Factor.
"Playing my own music is a massive thing me," he told DigitalSpy. "I learned to play instruments before I could sing. Originally I played the drums actually.
"But I'm never comfortable without an instrument. I think if I'd gone on X Factor without a guitar I'd have made a proper fool of myself."
The singer insisted: "It isn't just hiding behind it, though, it's an extra way of expressing myself through the song. It's a lot easier to put your own spin and feeling on a song if you can dictate how a song goes."
Sam also teased that he would also like to show off his piano playing skills if he makes it to the live shows in May.
"I don't want to do something for the sake of it, but if it helps the song and it's right for the performance, I'd like to do it," he added.
Britain's Got Talent 2012 auditions continue this Saturday night on 2012