One Direction find it difficult to come up with a unique sound.
The British boyband - comprising of Niall Horan, Liam Payne, Harry Styles, Zayn Malik and Louis Tomlinson - are currently promoting their new album Take Me Home.
Their 2011 single What Makes You Beautiful has been likened to Grease's Summer Nights, while the opening riff of latest track Live While We're Young resembles The Clash's Should I Stay or Should I Go.
"It must be quite difficult to do a unique riff now because there have been so many songs," Louis told the BBC.
"Surely there are only so many riffs you can pull out, no?"
Harry added: "It's kind of on purpose though. It's a great riff so..."
The video to the boys' new single features them having a water fight as they sing "let's go crazy, crazy, crazy".
Harry says the message of the song is the most important part.
"It's about living while you're young. It's just about having fun. Not taking life too seriously, just enjoying yourself," he explained.