I'm sorry, but how can you even compare these two. Based on Christina's tone alone, her voice will always be better than Beyonce's. You know, most of the time, it's not about the 'notes'. It's about the power, the emotion, the level of deepness and how you deliver it with your voice. Beyonce's voice is nice, but that's it. Christina's voice is something unique, mind-blowing, completely unforgettable. That's why she's called the voice of our generation.