4:13 i don't know but it seems like jessie j wants to try the whistle on that part but she failed then she changed it to vibrato (i'm not sure co'z I'm not a vocal expert) . She is a Vocal Genius . i'm really a FANNNNN!!!!!
I'm sad because obviously there's nothing left between them when they sang this song. Emotionally, they're not connecting and the song ends up like ordinary. But I have to give it both to them, they're great singers in their own genre.
I love jessie but When compared to mariah , she falls short .... mariah voice may seem simple but its ridiculously complicated to duplicate . Mariahs tone can destroy every singer