For most of BTOB's songs, Changsub sings the beginning of the song. He is well-loved to MELODYs as the 'intro fairy' because his voice pulls listeners into the song within the first few seconds. For songs Changsub doesn't sing the beginning, Sungjae, the group's most well-known member, usually sings the beginning.
Even the members have talked about it, where Eunkwang explained, "Changsub is the master of relaying emotions. He's the 'intro fairy'. Hyunsik has strong high notes and a masculine voice. He has a rough charm. Sungjae is right in the middle. He's the middle we need that has his own color."
However, Hyunsik sings the beginning of BTOB's new title song "Movie", a song Ilhoon composed. It's almost unheard of for Hyunsik to sing the first part of BTOB's song, but Ilhoon explained, "I originally thought of Changsub-hyung or Sungjae for the beginning part. However, the song is in general very high, but that part is very low. Hyunsik-hyung sounds amazing on low notes, so I thought he fit it the best and gave it to him."