Who isn't multifaceted or doesn't like stepping out of her comfort zone when it comes to her sound, image, message. Whose songs bare the most familiarity, whose song when heard you can't help but feel you've heard a dozen that sound the same.
I forgot to add Kelly Clarkson, she's very inflexible as well.
I didn't add artists who have released only one or two albums, there isn't enough material to judge.
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