He compared the work of the remixers as ``as subtle as a jackhammer, whether it's on the metallic-flaked ''American Life`` by Headcleanr or the '90s-retro Nevins mix of ''Nothing Fails``. On all these mixes, Madonna sounds as if she's out of step with the music of 2003''. Erlewine also compared Spears' vocals with that of Madonna's during _her_ early days and Aguilera's with that of Cher's. <sep>, Pronoun: her