Perry, 27, is in the midst of planning a duet with her BFF Rihanna. "We've collaborated on a lot of things, but just not songs yet," the "Part of Me" singer said. "It's one of those things that's got so much build up that we have to deliver."
And Perry she knows just what she doesn't want the song to sound like. "I want it to be like that Eurythmics and Aretha Franklin song 'Sisters Are Doin' It for Themselves,'" she said of a classic female empowerment tune from 1985. "Not 'Beautiful Liar.'"
"Beautiful Liar" would be Beyonce's smash 2007 collaboration with Shakira, which hit number one on the Billboard Hot 100.
Perry added of her not-yet-record Rihanna ditty: "How disappointed would you be if that song came out and it's no good? Sometimes you have to wait for greatness."
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