Madonna Louise Ciccone Ritchie hardly needs any introduction. Over the course of a 25-year career she has impacted not only on the course of popular music but on popular culture itself.

Since her first hit single, Holiday, Madonna has passed through countless incarnations, changing image and sound at her considerable whim. She has always managed to court controversy, whether with the allegedly blasphemous video to Like A Prayer, or her sex-obsessed album Erotica and the accompanying book of pornographic photos, called simply Sex. But she's also managed to stay ahead of and influence trends in fashion and music and produce classic, enduring pop songs - from the self-mockery of Like A Virgin and the pure dance thrill of Get Into The Groove to the uplifting gospel of Like a Prayer.

She also possesses an uncanny ability to resurrect herself by tapping into the zeitgeist. Following the poor reception of her 1994 release, Bedtime Stories, she took time out, returning four years later with Ray Of Light, produced by English studio boffin William Orbit, which gave her the biggest critical success of her career. She followed this up with Music, collaborating with French producer Mirwais.

Madonna's live shows are legendary: the peroxide crackle and fizz of Blonde Ambition, the sleazy abandon of The Girlie Show and the jaw-dropping theatrics of Drowned World have been cited as ground-breaking in their innovation and spectacle. Her 2005 album, Confessions on a Dance Floor, sold millions of copies and the accompanying tour the following year was a huge critical and commercial success.