Idk how but they fit every song they performed at first i thought it was they kept the original song and just sang a few parts and the whole time they were lip singing but today when I happened to watch it again I realized that no they actually sang the whole song with their own voice idk how they did it because I saw the other covers too that other artists did off course it was amazing but it felt something was missing but when xin did this it just fits so well These girls are really very talented Love them❤