This week, 'The Voice' Top 8 reinvent themselves and deliver with standout performances while Usher shows off his sense of humor.

Judith Hill opened the show with will.I.Am’s ‘#ThatPower.’ Judith completely flipped the pop-electro song and reversed it by turning it into a funkadelic, R&B rendition. This experiment was the perfect way for her to show off she’s a chameleon as a performer.

Holly Hunter also took a chance by doing the up-tempo country tune ‘Done’ by the Band Perry. Her vocals were spectacular during the set and it was great to see her personality shine. But the true surprise moment came from Usher, who let his sense of humor shine when Carson Daly called him Urkle for sporting thick framed glasses. The crooner didn't hesitate and gave a hilarious reply, calling him Jimmy Neutron. Carson does look like Jimmy Neutron!

Judith Hill, Michelle Chamuel, Sarah Simmons and Sasha Allen took on Rihanna’s ‘Diamonds’ together in a mundane rendition of the song. The Swon Brothers started off shaky as they were ahead of the backup singers with ‘Seven Bridges Road,’ but their harmonies were great with this song choice.

Sasha Allen blew Usher’s ‘Without You’ out of the water when she came onstage with her big hair and voice. She hit all the top notes effortlessly. Usher admitted he was biased by the performance. According to him, she “invoked the emotions” of the song.

Sarah Simmons is normally raw and rough around the edges but she softened up with Gotye’s ‘Somebody That I Used to Know.’ Every now and then she’ll throw in her Janis Joplin-esque vocals but this is the one time where the song showcased her beautiful voice.

Michelle Chamuel continues to deliver, wearing her emotions on her sleeve with a theatrical rendition of Bruno Mars' ‘Grenade.’ It was hands-down the best performance of the night. After so many memorable and risk-taking performances, Danielle Bradbery didn’t stand out when she performed 'Grandpa (Tell Me ‘Bout the Good Ol’ Days).’ There was nothing special from the performance.

Adam Levine wanted his team member Amber Carrington to step away from her country background and take on Adele's ‘Skyfall.’ Even though Adele is one of those artists you never touch on a singing competition, Amber did her song justice.

Tonight's episode will find two contestants being eliminated for the quarterfinals.

Watch 'The Voice' Season 4, Episode 20