U.S. singer Madonna performs during her "Sticky and Sweet" tour at the Olympic stadium in Athens in this file photo from September 27, 2008.[Agencies]

The Madonna concert ended nearly 12 hours ago, and this reviewer is still tired. And that's just from watching.

The 50-year-old Material Girl has metamorphosized into a lean, mean machine of muscle and sinew. That pumped-up toughness also is evident in her music as performed in this latest arena extravaganza, dubbed the Sticky and Sweet tour and promoting her recent CD "Hard Candy."

That album is generously highlighted in the course of the two-hour show, a good half of which is devoted to such cuts as "Candy Shop" (the opener, in which Madonna makes her entrance while seated on a throne), "Beat Goes On," "She's Not Me" and "4 Minutes."

She cherrypicks from her hits, forgoing most of her best-known tunes -- with the exception of such songs as "Borderline," "Into the Groove," "Ray of Light" and "Like a Prayer." Most of these are dramatically rearranged to give them a harder-rocking edge, with heavy doses of electric guitar and thumping bass beats. As with the performer herself, the sweetness in them seems to have been drained away.

There's a relentless drive to the proceedings that is almost unnerving. The headliner almost never stops moving, constantly whipping through intensely choreographed set pieces with her corps of backup dancers as if determined to burn off a certain number of calories per show. At one point, she even showed off her Double-Dutch jumping-rope skills.

She doesn't let the audience rest, either. Late in the show, she refused to begin one song until she had made sure that everyone in the massive arena was on their feet.

The one relatively quiet interlude was more bizarre than restorative. It featured an acoustic, Gypsy-flavored rendition of "La Isla Bonita," followed by the evening's sole ballad, "You Must Love Me," from the "Evita" soundtrack.

The singer showcased her physique in a series of revealing outfits, though they were mostly more redolent of the gym than the usual S&M garb.

Unlike her most recent go-around, there was little in the way of controversial material on display, with nary a crucifixion in sight. The one exception was the video montage accompanying "Get Stupid," which interpolated images of Barack Obama with figures like Nelson Mandela and John McCain with, among others, Hitler.

The Sticky and Sweet tour plays Dodger Stadium in Los Angeles on November 6.

(China Daily/Agencies October 9, 2008)