The Glee alum is hard at work on his first full-length solo album, and though he’s now confident in his talent, Overstreet admits he was once a shy performer – and credits the series with turning things around.
“I was still afraid to sing in front of people before Glee,” he tells PEOPLE in this week’s issue. “I got really nervous when I did my audition [for Glee], my leg wouldn’t stop shaking when I was singing.”
Overstreet, 28, played singing jock Sam Evans on the series, which he joined in season two.
“It was a bootcamp in the best way. I learned more than I could have ever learned from acting or singing classes,” he says of performing as part of Glee‘s fictional New Directions.
He adds, “I couldn’t get that experience anywhere else. I definitely became a better singer, from singing in the studio every day and watching people that are great performers that were coming onto our show.”
And his new musical offerings first took root before the series even aired its final episode in 2015. Overstreet says that in between takes on the show’s choir room set, he was busy jotting down lyrics.
“Then I’d go into Matthew Morrison‘s office and try them on the guitar,” says the star.
Of his new music, Overstreet tells PEOPLE, “I don’t really like to put stuff in a box as far as genre specific.”
“For me I like telling stories,” he adds. “I’m going to make it as fun as possible. I just want to be able to show my personality and let people get to know me.”
Luckily, Overstreet has a great source for musical guidance: his dad, songwriter Paul Overstreet – a two-time Grammy winner and five-time winner of BMI songwriter of the year.
“He gives fatherly advice but I also really value his opinion on a professional level,” the star tells PEOPLE. “I like running my stuff through a filter.”
Overstreet says he loves “experimenting” with different sounds while songwriting, but wants to be an innovator with his music.
“My dad knows great music,” says Overstreet. “So I’m taking music to him to get an opinion rather than praise. He’ll be like, either, ‘I think this is a great song’ or ‘I think you have better songs.’ ”
Overstreet’s new music video for the remix of his single “Hold On” hits the Internet on Friday.