1. Kim Hak-chul, better known by his stage name Kim Yeon-woo is a South Korean male singer, vocal coach, and professor at Seoul Art College.

1. Kim Hak-chul, better known by his stage name Kim Yeon-woo is a South Korean male singer, vocal coach, and professor at Seoul Art College.
In 2011, Kim Yeon-woo achieved widespread fame and recognition in South Korea through his participation on I Am a Singer, along with numerous appearances on variety and entertainment shows.
In 1996, Kim Yeon-woo became the featured vocal of You Hee-yeol's project band Toy and adopted his stage name Kim Yeon-woo, which was the name of a cafe You Hee-yeol frequented.
Since leaving Toy, Kim Yeon-woo has released five solo full albums and two mini albums.
In 2010, Kim Yeon-woo was noted in the media thanks to a video of him performing at a university concert back in 2007.
Kim Yeon-woo performed in the heavy rain while holding an umbrella, after all the other guest singers had reportedly quit.
Kim Yeon-woo's popularity started to rise, and he gained widespread recognition from the public, earning the nickname God of Vocals.
Kim Yeon-woo found success in two other guest appearances in the contest.
In 2012, Kim Yeon-woo participated in the second season of I Am a Singer.
In 2015, Kim Yeon-woo sang a duet with Yangpa in the third season of I Am a Singer.
Kim Yeon-woo's popularity rose even more thanks to his participation in King of Mask Singer.
Kim Yeon-woo studied practical music at Seoul Institute of the Arts.
In 2010, Kim Yeon-woo married the daughter of a president of a Korean corporation.