There's no denying the absolutely rad amount of fun that the sibling team of Flosstradamus and Kid Sister have when performing together. We witnessed the radness firsthand when they teamed up late last month for a gig at NYC's Webster Hall.

In what has become somewhat of a "musical rite of passage", children's television program, Yo Gabba Gabba!, acts as an avenue for established and up and coming artists to break into the homes and hearts of families with young'uns.

This past weekend, however, the Youngs (Josh and Melisa) took it one step beyond the television and joined the YGG cast of characters on stage in Chicago. Check out the video below, and stay tuned til the 2:56 mark, when you get a sneak peek at Floss' backstage rehearsals!

Did you catch Biz Markie drop by for a shimmy and shake? Adorable!

mp3: Kid Sister - Girlie Rock (Flosstradamus Remix)