Britney Spears is "very stubborn" when it comes to making music.

The 'Hold It Against Me' hitmaker - who is poised to release seventh studio album 'Femme Fatale' - said it's taken her three years to follow up 2008's 'Circus' as she will only sing on tracks she "loves."

She said: "I have always been heavily involved in every album I have ever made. I'm very stubborn when it comes to recording and will only record songs I love, which is why it takes me a long time to make an album.

"I have to feel connected before I record and the song has to spark something inside me. Very few songs do that. I guess it's a good process because I love all of my music. I know there are a lot of artists that hate songs they recorded. I don't feel that way."

The 29-year-old singer - who worked alongside producers Max Martin, Dr. Luke and Black Eyed Peas' will.i.am on tracks for 'Femme Fatale' - admitted she was keen to give the record a "darker and edgier" feel.

She added to Rolling Stone magazine: "When we first sat down to talk about 'Femme Fatale' I knew I wanted to make a dance album that was ahead of everything else out there, but unique to me, which is why I was so picky with the recording process.

"I also wanted to make sure that this album was completely different from 'Circus' or anything else I had ever recorded. I love 'Circus' but I wanted something darker and edgier."

'Femme Fatale' is released on March 29.