what if.. what if.. if….. _ _ . . …_ …_ … ._ _. …. _ [Credit] Produced by Diett Lyrics by BlueWhale Composed by Diett Arranged by Diett Piano, Drum, Bass by Diett Guitar by 최지상 Whistle by 이현준 Mixed by Diett, BlueWhale Mastered by Headbang Studio ArtWork by shutmyeyes, Harim