Ask anyone 10 years ago and they would have said nobody can hold a candle to Mariah, but it has become very apparent that Mariah's vocal prowess has deteriorated some and I have found none of her performances in recent memory to be very impressive.
And honestly, I've always just preferred Beyonce's voice. She has and element of showmanship in her voice, but the difference is that Beyonce uses her voice appropriately. Her voice is not exaggerated with obnoxious "belting" ala the Christina wannabes or whistle register gimmicks ala the Mariah wannabes.
Mariah wins. Beyonce is overrated as a vocalist. She's brilliant but not in the same league as Mariah, Whitney, Celine etc. in their PRIME imo. And Mariah's studio vocals are still very solid for the most part. She's maintained the 4 octaves & some notes on each album since the 90's.
