Rita Ora's new single was written after she started humming with boyfriend Calvin Harris.

The 'Hot Right Now' singer described her beau as ''incredible'' and says it felt completely ''natural'' when working together on her new track 'I Will Never Let You Down', which is featured on her second studio album.

Speaking on DJ Nick Grimshaw's BBC Radio 1 Breakfast Show, she gushed: ''The song I'm going to release features an incredible talent in Calvin Harris. It's one of the coolest songs I've ever heard.

''Honestly it was so natural. I wouldn't have done if it didn't make any sense. We were sitting at home, he started humming then I started humming then we hummed together!''

Calvin Harris isn't the only star the 22-year-old singer has lined up for her record, as she also revealed 'Same Love' hitmakers Macklemore & Ryan Lewis have made a contribution.

Meanwhile, Rita admitted she was anxious ahead of the Grammy Awards in Los Angeles last week, adding that she went to support her beau Calvin, who received two nods for Best Dance Recording and Best Dance/Electronica Album.

She explained: ''The Grammys, I was actually really nervous. It was the first time I'd been. I have an ego you see, I didn't want to go unless I had something to do with it like a nomination or something, like any musician. I went there to support a partner and explore it [and] it was exciting.''