Think Blue Man Group except White. And rather than produce sound with just about everything except their voices, they use only their voices to produce just about every sound (see: "Scratcher" competing with his big brother "Beat On").
I have seen my share of A Cappella groups. I have seen my share of off-Broadway shows. I have never seen anything with as much creativity and audience participation as this one- be prepared to warm-up, sing, touch your neighbor, have the music playing in your head broadcasted to the audience, and possibly even be serenaded on stage. From history to cinema, love and even death, Voca people pretty much have every topic covered in very clever arrangements. Be sure to bring your energia!