Shawn Mendes & James Corden Throw Down in 'Better Then/Better Now' Riff Battle

Shawn Mendes & James Corden
Terence Patrick/CBS

Shawn Mendes performing with James Corden during The Late Late Show with James Corden on Sept. 28, 2016. 

Shawn Mendes and James Corden agree on one thing: the music of their youth is the best. So on Wednesday night's (Sept. 28) The Late Late Show, Mendes, 18, just had to interrupt when Corden once again hit his "This is How We Do It" button during a behind-the-desk dance party. "I just noticed you never play new music," said Mendes. "You know, Backstreet Boys yesterday. 'This is How We Do It.' It's just like old stuff all the time." 

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Corden corrected his youthful guest by reminding Mendes that "everybody knows music was better back then than it is now." And then it was on. Mendes challenged Corden to a "Better Then/Better Now" riff off, with a cappella backing from The Filharmonic. The battle was fierce, invoking hits by Calvin Harris, the Spice Girls, Kriss Kross and Sia. In the end, though, the pair spanned the generation gap by mashing up a TLC classic with Mendes' "Stitches." 

Check it out:

Mendes also performed an emotional take on his current single, "Mercy."