A month ago, I rated the Sing-Off group Pentatonix as a black horse after hearing them sing three songs on the show. It has been a month and the group has skyrocketed to front runner by a mile. The group is so talented, creative and versatile that they have been able to deliver top notch performances despite having every genre of music being thrown at all the groups. Rock and Roll, Country, R&B, Pop, you name it, Pentatonix has nailed them all. Heck, in the recent week some of the groups have taken to blatantly imitating Pentatonix's signature style in a bid to stay in the competition. That is probably the ultimate compliment any competitor can give to Pentatonix.

If you don't follow The Sing-Off, here's what you have been missing out.