What do you think is the hardest Kpop song to sing? I noticed that when junior groups cover songs, or when there's a survival show where groups cover songs, they tend to almost never sound as good as the original. Mainly because a song from most groups cater to that group's vocal ability (usually not always). Girl Groups: ? Boy Groups: EXO | Wolf you need major pipes to be able to sing the end of the song (timestamp included) the remix is even harder.