05.17.13 11:45 AM ET
Frankie Valli Can Still Sing
At 79 years old, the lead singer of the 'Four Seasons' may be in his golden years, but he's still got a golden voice. Thursday night, Valli joined the season finale of 'American Idol' and proved that, unlike the show, he hasn't fallen off. Watch him croon 'Can't Take My Eyes Off You.'