Moon Seung Hyuk, later legally changed to Moon Dong Kyu, is a South Korean singer, dancer and former member of UNDERDOG (언더독) and SPECTRUM (스펙트럼). He graduated from Dankook University with a bachelor's degree in Business Administration.

He was part of Inter B.D. Entertainment as a trainee and was set to debut as the vocalist of D.I.P (디아이피). However, he decided to leave the company in May 2016, just 6 months before the group debuted.

He then moved to 2ABLE Company (투에이블컴퍼니) and made his debut in September 2016 by joining UNDERDOG. The group had debuted in 2013 but faced constant lineup changes. He promoted with the group and attended events, but they never released new material while he was part of it. Ultimately, the group quietly disbanded in mid-2017.

He then re-debuted in May 2018 as SPECTRUM's lead vocalist with their first EP, "Be Born". However, shortly after their debut, member Kim Dong Yoon passed away, which generated instability inside the group.

Later, the lack of activities due to the COVID-19 pandemic forced Wynn Entertainment (WYNN 엔터테인먼트) to announce the group's disbandment in 2020.

He was trying to become a musical actor, but no new information regarding his activities has been revealed.

(Source: MyDramaList) Edit Biography