Christina Aguilera and Justin Timberlake

While Christina Aguilera sufficiently undermined a respectable (if not quite illustrious) first outing with last year's unfortunate Stripped, a follow-up that tried to out-pink Pink, Justin Timberlake merged independence and accessibility on Justified, his confident, engaging, mature solo debut after so much *NStink.

Anyone with a fondness for Off the Wall-era Michael Jackson can appreciate what Timberlake, the Neptunes, and Timbaland pulled off on Justified. Aguilera, in sharp contrast, wanted to be considered a grown-up so badly that she went for shock, as if trying to scare us into taking her seriously. The resulting songs are mostly bleating tirades about the need for personal freedom, the equivalent of the spoiled rich girl whining for the keys to her dad's Jag.

This performance will be the first stop on the two developing stars' summer U.S. adventure together, and although we can expect the usual helpings of spectacle, choreography and fancy sets, at least with Timberlake there is also an unquestioned level of craft and care worked into the material. In the case of Aguilera, we can only wonder just how much more naked she can possibly get in order to keep us interested.