Demi Lovato was "stoked" about her track with Missy Elliott and Timbaland.

The 'Skyscraper' singer didn't initially expect to work with both the rapper and producer - who, as a team, were two of the biggest hip hop stars of the 90s and launched the career of Aaliyah - on the song 'All Night Long', but was excited when Missy requested to rap on it.

She told MTV: "I was so stoked when I went into the studio. I was working with Timbaland, and Missy was there, and she was like, she heard one of the songs and she asked if she could rap on it.

"And I was like, 'Of course, that's not even a question.' And she did, and she killed it."

She describes the track as a "fun" song, very different to the confessional lyrics of 'Skyscraper'.

She added: "Timbaland's actually on it, too, and it's fun. It's about staying up all night long and singing it to the boy that you like, and it's flirty and fun and it's not too grown-up, but it's grown-up enough."

Demi's new album - which also features collaborations with Jason Derulo and Iyaz - 'Unbroken' comes out later this month.