Singer Rihanna has said her new album will be unexpected and she feels "really optimistic" about it in a rare interview.

"I know it's not going to be anything that anybody expects," she told Harper's Bazaar.

"And it's not going to be commercial or radio digestible. It's going to be where my artistry deserves to be right now."

The 37-year-old has kept fans waiting for years for her new album. Her eighth studio album, Anti, was released in 2016.

There have been plenty of rumours about what direction the long-awaited record will take, including talk of it being a reggae album.

But Rihanna, whose real name is Robyn Fenty, was quick to dispel those.

"Way off! There's no genre now. That's why I waited. Every time, I was just like, 'No, it's not me. It's not right," she said.

"This much time away from music needs to count for the next thing everyone hears. It has to count," she added.

"I cannot put up anything mediocre. After waiting eight years, you might as well just wait some more."

While not revealing any more, she told the magazine that she was "feeling really optimistic.

"I feel like I've finally cracked it, girl!," she said.

The multi-Grammy Award winner, who began her career in 2003, is best known for songs such as Umbrella, Shut Up And Drive and What's My Name?

Despite stepping away from music in recent years, she has been keeping busy with her make-up and skincare brands.

• Rihanna says fashion has helped her personal 'rediscovery'

In the interview, she said she was focusing on living in the moment.

She also shared her thoughts on growing older, using an expletitive to describe the process, while saying "it's also a blessing".

"My legacy is right now. That's all I have the most control over. My legacy is what I do with my time at this moment".

Rihanna has two young sons, RZA and Riot, with her longtime partner, rapper A$AP Rocky.

Earlier this week, the musician, whose legal name is Rakim Mayers, was found not guilty of firing a gun at a former friend by a jury in Los Angeles.