In reply to Scoopz.

@Scoopz agree with your picks. . . except on Ariana having a lighter voice than Jessie J---the latter is (an untrained) coloratura, i.e. the lightest voice type there is.

Surprisingly, I see Tamar fill Xtina's mighty shoes. Case in point is her live rendition of Lady Marmelade's explosive climax here: https://m.youtube.com/watch?v=LKgpdMqMZVs