In terms of sheer power Christina is pretty much tops for vocalists. Not many singers can out muscle her voice, so in terms of aggressive singing style she would be a stronger vocalist then Beyonce. That's just fact. Beyonce sounds better though and has a much better technique and way of singing. Hence why she hasn't accumulated as much damage to her voice as Christina has to hers.
In terms of sheer power Christina is pretty much tops for vocalists. Not many singers can out muscle her voice, so in terms of aggressive singing style she would be a stronger vocalist then Beyonce. That's just fact. Beyonce sounds better though and has a much better technique and way of singing. Hence why she hasn't accumulated as much damage to her voice as Christina has to hers.
Sia