Korea's female singers are joining the craze of singing Disney animated film Frozen's OST "Let It Go." Each singer brings a different feel to the song with their unique vocals, creating a wide variety of sounds. But the question has to be asked: Who sang it best?

The first female singer to start the "Let It Go" craze is SISTAR's Hyolyn. She sang the song in an official Korean version. Her voice was also featured in the ending credits of the actual movie. Hyolyn initially didn't have plans to officially release the song, but as the song exploded in popularity, she decided to release her own version. As much as Hyolyn has the best voice in SISTAR, her version of "Let It Go" went viral, too. This was thanks to her ability to accurately convey the emotions to go along with the song's lyrics.

Ailee recently appeared on KBS 2TV "Yoo Hee Yeol's Sketchbook" and sang "Let It Go." At the time the song wasn't very well known, but as the OST started picking up speed, her rendition is being revisited by listeners. The video containing Ailee's singing of the song recorded 500,000 views on YouTube, as of the 5th.

Female duo Davichi's Lee Haeri challenged herself to sing this OST as well. She appeared on "Shannon's Small Concert" on the 29th and sang verse 1 of the song. Her rich and distinctively emotional voice put a different twist on the song. The video clip of Lee Haeri singing the OST recorded over 200,000 views on YouTube, as of the 5th.

Girl group Kiss & Cry's Dia posted a cover of "Let It Go" on her Twitter. She presented her clear voice in her rendition of the song, and quickly rose in rank on portal site search queries. As of the 5th, her video has over 400,000 views on YouTube.

Cable channel Mnet's "Voice Korea" winner Son Seung Yeon sang "Let It Go," too. On February 4th she posted a cover of the song on her Twitter account, which was met with praise from netizens. Her extraordinary singing power allowed her to sing the song even while sitting down. She showcased her explosive low notes and a full range, all the while making it look easy. Her cover video was featured on one of Facebook's popular pages, recording over 400,000 views in just 9 hours of it being published.

Hyolyn, Ailee, Sog Seung Yeon, and Lee Haeri are well known as being amazing singers, and there's anticipation as to which other female singers will be joining in on the "Let It Go" craze. Who do you think sang it best?