Former 'Nsync star Jc Chasez thrilled a group of California college girls after turning up unannounced to perform at a sorority dinner.

Members of the University of Southern California's Delta Delta Delta organisation were enjoying a meal when Chasez showed up to sing.

The surprise stunt was apparently organised by a few fraternity students, who arrived in smart suits to sing The Lumineers' Ho Hey with Chasez, accompanied by an acoustic guitar.

In footage of the evening, which was filmed and posted on YouTube.com, Chasez joins the fraternity hunks in handing out roses to the stunned sorority beauties after they belt out the sweet tune.