Creating the melody for naughty Cee-Lo Green hit F**K YOU came so easy to pop star Bruno Mars, he feared he'd accidentally ripped it off from a forgotten 1970s tune.
The singer/songwriter admits he half expected a plagiarism charge as the track became a worldwide Internet smash.
He tells Rolling Stone magazine, "We kept singing, 'I see you drivin' 'round town with the girl I love, f**k you...' Then I went to the piano and came up with the piano riff.
"I actually thought the riff was an old '60s or '70s soul riff, but I guess I'd know by now if it wasn't original."