Back in the headlines after her controversial assault in February at the hands of ex-boyfriend Chris Brown, 21-year-old R&B star Rihanna is currently touring the world promoting her fourth album, the saucy Rated R. According to Nuno Bettencourt of American rockers Extreme (remember “More Than Words”?), the Barbados-born starlet wanted to make an album that rocked hard and was influenced by heavy metal – but her label, Def Jam, had a “seizure” and wouldn’t let the collaboration take place.

“I’ve been asked to play with pop artists in the past but turned them down because they didn’t really get the vibe,” Bettencourt told the Daily Mail this week, after appearing onstage in London with the “Umbrella” star. “But when I spoke to Rihanna she was totally into transforming herself into a heavy rock chick. I think the label had a seizure so they went down another route.”

Rated R is released worldwide tomorrow.