The right tag is 악동뮤지션.
Akdong Musician (Hangul: 악동뮤지션) is a South Korean band, consisting of siblings Lee Chan-hyuk (Hangul: 이찬혁) and Lee Soo-hyun (Hangul: 이수현). They are known as the winners of the second installment of the K-pop Star series.
Instruments: acoustic guitar, lead vocals, backing vocals
Born on 12 September 1996, Chan-hyuk is the group's lyricist and arranger, as well as provides vocals to their songs.
Instruments: lead vocals, backing vocals
Born on 4 May 1999, Soo-hyun provides the main vocals of their songs.