Comfort is important for human beings. We all crave the comfort of familiarity and routine. We like comfort foods and comfort clothes. We crave it. We need it. The coaches on 'The Voice' threw comfort zones out the window this week, constructing uncomfortable and unpredictable battle round scenarios. In most cases, the decision to go against the grain paid off in worthwhile dividends.

Christina Aguilera had two of her female team members engage in battle with Rihanna's 'Only Girl (In the World).' Xtina pitted Raquel Castro, who starred in the flop 'Jersey Girl' and is the youngest voice, against So-Cal gal Julia Eason. Both young ladies can sing for their supper, and Aguilera was looking for her team to be bolstered by the infusion of youthful, fresh energy that is emblematic of a risk-taking pop star like RiRi. There were pitch problems -- what, is this 'American Idol'? -- but it was Castro who moved on.

Blake Shelton wanted to entertain people, and said Dia Frampton and Serabee probably couldn't envision themselves singing a Motown standard, since it's so far outside of their comfort zones. But Shelton was all about shaking up comfort zones, a move which can yield the best performances if handled properly. Shelton team advisor Reba counseled the girls on their concerns, one of which was stage fright. Reba said that stage fright is good since it keeps you on your toes and alive during your performance. Frampton and Serabee were so polar opposite during their battle, proving that it truly is about 'The Voice.' Pretty Dia was the quiet victor.

Adam Levine, like Shelton, shook things up and purposely made his team members uncomfortable by assigning them Radiohead's droney, early '90s hit 'Creep,' which was dark and ominous. Those qualities are the opposite of what Devon Barley, who is a med student, and Rebecca Loebe, a traveling musician who resides in her car, embody. This was the weakest of the battles, even though Levine was so impressed by his charges that he couldn't make a choice. He eventually picked Barley.

Cee Lo Green said that "competition does not always come to meet you where you are comfortable" and he, like Levine and Shelton, was about shaking the foundation and making his team members go against the grain of what they like and are used to. He pitted Kelsey Rey against bubbly sisters Tori and Taylor Thompson in the ring. He wanted to teach the sisters how to share a melody and a song, and for Rey not to get lost by the fact that she was outnumbered. They ended up performing like they should do so all the time: as a trio! The sisters prevailed, though.

Watch 'The Voice' Battle 3 Episode