Crooner Bruno Mars has revealed what the most "important ingredient" is when it comes to his musical inspiration.

The international star performed a live rendition of new album 'Unorthodox Jukebox's' lead single 'Locked Out of Heaven' during 'MTV First: Bruno Mars' last night (December 11).

Mars has revealed the inspiration behind his second studio album.

He explained to MTV News: "I don't know, I like to go into the studio and how I feel, that' s what comes out in my music.

He continued: "One day I feel like this, another day I feel like that. I think the most important ingredient is for me to have fun going into the studio and by me being unorthodox — that's what my music sounds like."

Mars recently joked 'Locked Out of Heaven' was inspired by Halle Berry after explaining the inspiration behind the song's raunchy line 'Your sex takes me to paradise' during an interview on Capital FM.

Mars is set to perform new single 'Young Girls' today (December 12) during an eight-hour live stream for 'The Big & Best of 2012: A Year End Celebration Presented by T-Mobile'.