After tuning into my first televised musical competition last Spring with The Voice, I signed on for my second this Fall with The Sing-Off.

In an era of Auto-Tune and processed pop stars, there is something very refreshing about a competition that features nothing but the human voice. And the a capella groups featured on this show do jaw-dropping things with those voices.

My favorite competitors — and the group that went on to win the title — were Pentatonix, a 5-piece group of teens and 20-somethings who hail from Texas. They put on a clinic week after week, nailing every genre assignment thrown their way.

I couldn’t decide between two of my favorite Pentatonix performances for today’s blog entry, so I’m featuring both. First up is ‘Let’s Get It On,’ showcased during R&B Week. I find the judges’ reactions to this one as enjoyable as the song (particularly when Sara Bareilles is moved to drop an F-bomb).

That clip is followed by a performance of The Buggles’ ‘Video Killed the Radio Star,’ delivered during Guilty Pleasure Week, that shows how innovative Pentatonix was in its arrangements.