Out singer Adam Lambert has called his coming out “an act of defiance.”

The 37-year-old Lambert came out on the cover of Rolling Stone after finishing as runner-up on the eighth season of American Idol.

He is currently promoting his fourth studio album, Velvet: Side A.

Speaking with the BBC, Lambert discussed how he was feeling while competing on American Idol in 2009 as rumors swirled about his sexuality.

“It was stressful and it was confusing,” he said. “I was like, 'What am I supposed to do?'”

“In hindsight, I realize there is power in coming out. The act of declaring your sexuality publicly, once you're a public figure, is an act of defiance in some ways, and it's also a form of activism,” Lambert said.

On Sam Smith, Lambert said: “Sam is a really interesting example because they have been able to be fully mainstream. I mean, mums and dads are buying Sam's album. That's a big move, a big step.”

He also praised Taylor Swift's LGBT activism.

(Related: Taylor Swift says conversation with Todrick Hall led to her speaking out on LGBT rights.)

“[S]he called people to action. She got a ton of signatures on a petition for the Equality Act,” he said, referring to a stalled federal LGBT protections bill. “That's real action, so it's not just for personal gain. She's putting her money where her mouth is. And I thought that was really admirable.”