So Ji Sub does an impressive job of playing the cold distant president of Kingdom Mall in the popular drama "The Master's Sun."

With a dismissive flick of his hand that makes it look like he's swatting a fly, he can tell poor ghost-tormented Gong Hyo Jin to get lost.

He was also a distant, secretive character when he played the dual role of detective/cyber hacker Kim Woo-Hyun and Park Gi-Young in "Phantom."

But if you are only discovering this actor in "The Master's Sun," there's a whole other side to him that you may not know about.

Like many kdrama actors, he also has a musical career and it's one that may not mesh with your image of him. While you might suspect that he could sing a subtle ballad, what he likes to do best is rap.

He's a big fan and has performed with hip-hop artists such as Bobby Kim from the group Buga Kingz. Kim provided some vocals on So Ji Sub's 2012 song "That Day A Year Ago" and the singer is a fan of So's rap style.

"His rap was rhythmic and unique," said Kim. "His music is top notch."

So has performed with other artists of note.

On his mini album released this past January, So Ji Sub raps in the ballad "Picnic" with pop singer Younha providing the melody. And in the music video for "Pick Up Line," he's a tongue-in-cheek cheesy pick up artist. It's worth checking out on YouTube if only for his uncharacteristic hairstyles.

According to his former agency, BOF, So Ji Sub has a unique voice tone that makes you feel like you are having a conversation with him.

"He combines singing and rapping and expresses emotions that make you feel like you are watching a romantic drama," said a BOF representative.

So Ji Sub did not even launch his rapping career until he was approaching 30. He released his first hip hop song, "Lonely Life," in 2008.

Performing hip-hop music has always been one of his dreams but he would never have tried it if he had not already been established as an actor and model.

"I wouldn't have been able to pull it off if I thought it was my main line of work," said So, who performs under the name G-sonick.

While his fans have mixed opinions about his rapping, they are happy that he's getting to live out his dreams. As long as he does not give up his day job in dramas, because he's really very good at that.