Leave your tap shoes at home, because if you bring them to “Song & Dance,” now playing at Ashland’s Oregon Cabaret Theatre, you will be jumping up on the stage and tapping with Christopher George Patterson. “Song & Dance” is a not-to-miss, high-voltage creation of Cabaret Artistic Director Jim Giancarlo. It features many time-honored musical theater favorites and some original songs by Giancarlo and Eric Nordin. While Patterson is a show-stopping dancer, Kymberli Colbourne belts out songs with a volume like Ethel Merman. The performers are neither young nor slim. But they both have the chops to carry this fast-moving …