This Day in Welk History: January 6, 1968

The duo of Sandi and Sally made their national television debut...

Fresh out of Brigham Young University, these pretty young ladies joined the show from an open casting call at the Hollywood Palladium.

The episode that Saturday night? That's Showbiz

Their first number ever sung? Zip-a-Dee-Doo-Dah

And from that point on, they never looked back.