Christina Aguilera, Wembley Arena, London

William Faulkner once wrote: "I'd rather be in hell than anywhere where you are." I now know how he felt. I wouldn't wish tonight's opening three numbers, off Christina Aguilera's concept album (those dreaded two words), Back to Basics, on anyone. The album is the "dirrty" girl's attempt to reinvent herself as a sophisticated vamp, as well as being a homage to the music of the Twenties, Thirties, Forties and Fifties, and to icons such as Ella Fitzgerald. It's wretched.

The tiny 25-year-old "diva" - an epithet she's had since her Disney days with Britney Spears and Justin Timberlake - had a suitably grand entrance, emerging on a flight of stairs in a white suit and trilby. It was met with an almighty screech from the crowd. Backed by a nine-piece band, three backing singers and a legion of dancers, the former Mouseketeer strutted and gyrated her way through "Ain't No Other Man". The sense of bluster set the tone for the night.

The concert was divided into three sections - entitled "1920s", "Circus" and "Duke Joint" - and the first one was the most baffling. While Christina warbled out her regulation pop numbers "Back in the Day" and "Understand" (which includes the ghastly lyric, "There are many walls you had to climb/If you really wanted to be mine"), images of jazz and soul greats - John Coltrane, Marvin Gaye, Louis Armstrong - were projected on to five huge screens. Needless to say, the songs bore no comparison to the icons shown.

Four tracks in and the combination of constant costume changes and frenetic song and dance routines had a pummelling effect on the soul. "Come On Over", from Aguilera's less noisome debut, Christina Aguilera, was more bearable. However, the volume was cranked up again with "Slow Down Baby", from her new album. One hoped she would just calm down. All this dashing about, getting changed into another sparkly number, then ripping off her clothes, felt a bit like cheating. Couldn't she just stand there and show off her four-octave cakehole?

Although Aguilera desperately wants to be taken seriously and is now happily married, she can still be grubby, apparently. While newspaper headlines such as "From French Queen to Squeaky Clean" were flashed up on the screens, Aguilera claimed to be "Still Dirrty". It was all very tiring.

Any highlights? Well, "Dirrty", her best song by a mile, was enjoyable, as were the more salacious numbers like "Candyman" and "Nasty, Naughty Boy". And on "Lady Marmalade" Aguilera appeared more relaxed, less painfully earnest. But there was no "Genie in a Bottle", her other good song. Plus, rather shoddily, she allowed the crowd to chant out her anthem "Beautiful". Which the night was not. In any way.