Bruno Mars felt like a "mosquito singing" when he recorded the Twilight theme tune last year.

The 26-year-old enjoyed a string of hits with his debut album Doo-Wops & Hooligans and is currently promoting second album Unorthodox Jukebox, out in December.

He recorded the single It Will Rain for The Twilight Saga: Breaking Dawn - Part 1 in 2011, but says he was not comfortable with the final mix of the track.

"I felt like I was a mosquito singing," Bruno explained to Billboard magazine.

"I don't want that to happen again."

The Just the Way You Are singer debuted his eagerly-anticipated new single Locked out of Heaven - taken from his second album - yesterday.

The star explained how important it is to him that his new material reflects his personality.

"This is me going into the studio and recording and writing whatever I want," he revealed.

"This album represents my freedom."

Bruno announced the completion of his second album to his 12 million Twitter followers last month.