The song was already hitting radio stations when fans noticed the similarities between her tune and Jimmy Eat World's hit The Middle, prompting Clarkson - a longtime fan of the band - to give the old song another listen.

She tells Rolling Stone magazine, "I didn't write the song (Heartbeat Song), I just sang it. But I didn't catch that. Nobody behind the scenes did. What's funny is that I was a huge fan of that Jimmy Eat World album."

Clarkson adds, "I thought it was really cool of Jimmy Eat World to say, 'Hey, no harm, no foul'. There are only so many chords."

And she admits the song similarities could have blown up into another rights battle - like the one between Blurred Lines hitmakers Pharrell Williams and Robin Thicke and Marvin Gaye's kids.

Gaye's family successfully sued Williams and Thicke over the similarities between their hit song and the late soul man's 1977 hit Got To Give It Up, winning a $7.3 million (£4.9 million) settlement earlier this year (15).

Clarkson says, "I felt so bad for Pharrell when he got sued - he's a huge fan of Marvin Gaye. and you know he didn't mean to rip him off. And he's the sweetest guy ever. It sucks."

Ironically, in the same issue of Rolling Stone, Taylor Swift names Jimmy Eat World's The Middle as one of the songs that inspires her, stating, "I remember listening to this on the bus to school. I felt comforted by it."