Every year, Billboard.com publishes a feature titled '21 Under 21', showcasing the staff's top picks for the world's hottest underage stars.�With the Wonder Girls showcased at 16th place last year, 4minute's HyunA continues the WG legacy by ranking 17th on the 2011 list. Aside from a minor date error in the last sentence, Billboard captured the singer's appeal in a one-page feature. �Check out what they had to say:

Why She's Hot: Nineteen-year-old South Korean pop singer HyunA got her start with pop girl group Wonder Girls�in 2007. After overcoming health issues, she left the group to become lead rapper and vocalist of 4minute and embarked on her own solo career. But HyunA's career really took off when she became the star of her own show. 2010 saw the debut of her first single "Change," and in July of 2011 she released her first mini-album "Bubble Pop!," the video for which was deemed "too sexy" for some Korean TV outlets. The controversial star displays a sexiness and stage presence far beyond her years, and is well on her way to becoming one of the key faces of the global K-Pop movement. HyunA, now a fixture in South Korean pop culture, is set to perform on the Korean version of "Dancing With the Stars" in June 2012.

Unsurprisingly, the list was topped by Justin Bieber, followed by stars including�Selena Gomez (#5),�Demi Lovato (#7),�Willow Smith (#14),�Greyson Chance (#15) and�Miley Cyrus (#21). Source + Photo: Billboard