by Todd Betzold

It is do or die time on The Sing Off, as the Top 4 compete to get to the finals and America's vote.

They start with another energizing group performance before getting into the good stuff. Each group will perform two songs this week: They will combine two current chart-topping songs into one seamless performance and then they'll sing one song chosen by the judges.

Up first is my favorite group, Pentatonix, who is a favorite to win this season and they'll be singing "Forget You" by CeeLo Green and "Since U Been Gone" by Kelly Clarkson. During rehearsal they struggled with the arrangement and stressed with this being a huge performance going into the final show. It was a great arrangement and I loved that, but they didn't seem as into it as they normally are. The bass guys were amazing.

The hip-hop group, Urban Method, is next and they'll be combining a sultry classic with a dance club hit, "Fever" by Peggy Lee and "Hot In Herre" by Nelly. This was a good performance, but after watching this I gained more respect for what Pentatonix did. There arrangement was seamless, where Urban Method's was not as seamless. The rapping was great in this song and the girls sang alright.

They started out as my favorite group, but Afro-Blue has been slipping the past few weeks in my ratings. They've been in the bottom two a few times, so this is a huge night for them. They'll be combining "I Believe I Can Fly" by R Kelly and "Fly" by Nicki Minaj. It had some soul and was decent, but I was disappointed again. There seemed to be too much going on during the mash-up and I didn't like the arrangement.

The Dartmouth Aires going big in their first performance, combining "Born This Way" by Lady Gaga and "Sympathy For The Devil" by The Rolling Stones. They have such a big group and have such strong stage presence they can make any song work. It was very entertaining and a great performance.

Now it is time for the judge's song choice and up first is Pentatonix. The judges chose "Dog Days Are Over" by Florence and The Machine. This performance gave me chills, the first time that has happened in a while too. Mitch, with his solo, may have wrapped this one up for a Pentatonix win. The whole performance was amazing and all work so well together...excellent.

For Urban Method, the judges chose "All Of The Lights" by Kanye West featuring Rihanna. Another excellent performance...Katie worked that mic so well and Mike handled his own with the rapping. The bass was great as well...good job.

Next up is Afro-Blue and for them, the judges chose "A Change Is Gonna Come" by Sam Cook. This was the group that I fell in love with at the beginning of this season. This was amazing and gave me chills. The lead was awesome and was effortless...these groups aren't messing around tonight...excellent.

Last up for the night are the Dartmouth Aires and for them the judges chose "Shout" by The Isley Brothers. This was another great performance...these boys can definitely put on a show on that stage...so much energy! The entertaining outweighed the vocals and I feel that's the point of an a capella group.

Now it is time for the judges to decide which group will be going home and after tonight's performances I feel bad for them to have to decide. The first two groups safe are: Urban Method and Pentatonix. That leaves Afro-Blue and Dartmouth Aires.

The judges claim they haven't made a decision yet, so the two groups must reprise what they feel is their strongest performance of the season and then they will decide. Afro-Blue goes first and sings "American Boy" by Estelle and the Dartmouth Aires sing "Somebody To Love" by Queen. Which group will advance? After some deliberation, the judges announce their vote: Sara voting for Dartmouth Aires, Shawn voting for Afro-Blue and Ben voting for Dartmouth Aires...so, Afro-Blue will be going home.

You can vote for the Top 3 until 9:00 a.m. EST on Sunday and the winner of The Sing Off will be announced on Monday's live finale at 8/7c on NBC.

(Image courtesy of NBC)

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