By Chris Heard BBC News Online Entertainment staff

Traffic came to a standstill as Madonna arrived in central London on Friday to play an exclusive show inside a record store.

Hundreds of excited fans lined the streets as the pop superstar turned up an hour late for the performance at HMV in Oxford Street.

A mood of mild hysteria greeted Madonna's arrival

There were shrieks as the beret-wearing singer emerged for an instant from a blacked-out BMW saloon and swept into the shop by the back entrance, surrounded by bodyguards.

Office workers hung out of upstairs windows hoping for a peek at the 44-year-old queen of pop amid a kind of mild celebrity hysteria.

A few hundred fans waiting at a side entrance for a glimpse of their heroine were disappointed when her car pulled up out of sight around the corner.

Squealing in anticipation, they dashed in search of her - but she had already disappeared inside to begin her band's soundcheck.

Madonna is promoting her American Life album

Wearing dark trousers and boots, her hair straight beneath her French-style hat, she did not stop to acknowledge the crowd of several hundred that had gathered.

She arrived in the west end of London shortly before 1600 BST - about an hour later than scheduled.

The 750 fans lucky enough to get tickets queued patiently in the sun as Madonna and her band began rehearsing tracks from her new album, American Life, in preparation for the 45-minute set.

Warm cheers and bursts of applause went up every time they were heard to finish a song from behind the shuttered doors of the store, which had been closed to the public since 1430 BST.

Several hundred fans waited for a glimpse

She was finally expected to go on to the small stage at about 1715 BST, ready to play about seven songs.

The set was expected to include the title song from her new album, along with fellow tracks such as Hollywood and Nothing Fails.

Among the first in the queue were friends Ana Taviera and Carol Sbeit, both 22, who had travelled from Montreal, Canada, especially for the show.

The two students paid $1,300 (�570) each to travel to London after learning about the performance in an e-mail from Madonna's fanclub.

"We slept here overnight," said Ms Sbeit. "We wanted to be at the front.

"I hope it will be worth it. We've been here quite a while now and we're suffocating a bit, but if our limbs hold out it should be OK."

Benjamin Davis is one of the lucky ticket holders for the London show

Friends Tomasz Zaremba and Isabel Munilla, both 27 and from London, had also slept out to be at the front of the queue.

Ms Zaremba, who saw Madonna perform on stage in London 15 times last year, said: "She's our idol. She's the best. No one can compare to her."

And her friend added: "She gets better with time, like wine. She's at her artistic and creative peak."

The 750 entrants wore wristbands that had been attached by security staff 48 hours earlier.

The bands had to be worn intact as a condition of the wearers gaining access.

At least one tout was offering a wristband for sale at �200 - and they were reportedly fetching twice as much on an internet auction site.

Despite the high levels of security, involving up to 50 guards and police officers, many fans waited in vain, hoping against the odds to get hold of a wristband.

Madonna's new album has had mixed reviews from critics

Gerardo Avila, 27, a fashion design student from Los Angeles, said: "The security guys said there's no way to get in. I'm hanging out hoping a miracle will happen!"

Despite reaching number one before slipping down the charts, Madonna's album has received a mixed response from the critics - and no shortage of outright hostility.

This was undoubtedly a successful PR stunt on Madonna's part in summery central London.

Whether the publicity will give the record another push is questionable. But just try telling the hundreds waiting here that Madonna no longer cuts it.