Avriel Benjamin "Avi" Kaplan won what show as part of the group Pentatonix?
Pentatonix:  Characterized by their pop-style arrangements with vocal harmonies, basslines, riffing, percussion and beatboxing, they are widely known for their covers, mostly of modern pop works or Christmas songs, sometimes in the form of medleys, along with original material. Pentatonix:  Pentatonix formed in 2011 and subsequently won the third season of NBC's "The Sing-Off," receiving $200,000 and a recording contract with Sony Music.
i don't know