In the recent episode of tvN's "Taxi" on January 18th, "Chilbong" Yoo Yeon Suk guested on the show and shared some of his behind the scene stories.

Kim Gura mentioned about the OST in "Reply 1994" that Yoo Yeon Suk, Jung Woo and Son Ho Jun took part in, to this Yoo Yeon Suk said,"Son Ho Jun is the best singer among the cast, since he was a singer before. He was a member of a group called Tachyon"

Then an old video of Son Ho Jun as revealed. He was in a three-member group named Tachyon. They debuted with a song called "Feel Your Breeze" but later disbanded due to the lack of popularity.