Kanye West stuns MTV ceremony with on-stage attack on Taylor Swift

With his preppy clothing and middle-class background, he was supposed to be the acceptable face of an artistic genre tarnished by its long association with guns, drugs and attitude. Instead, Kanye West finds himself cast as hip-hop's latest pantomime villain.

The rap artist is counting the cost of an impromptu decision to stride onstage at Sunday's MTV Video Music Awards, grab a microphone from award-winner Taylor Swift, and inform the audience that the gong she'd just won should have gone to someone else. To stunned silence, interspersed with the odd boo, West announced that his friend Beyoncé Knowles actually deserved the prize for Best Female Video for her track Single Ladies.

He then shrugged his shoulders and wandered off-stage, before security threw him out of the venue.

Described as "an astonishing rant" in some quarters, the hip-hop star's comments were in fact calmly delivered. But they nonetheless overshadowed not just Swift's speech, but the entire, multi-million dollar event.

On one level, West behaved like a classic playground bully, marching up to the petite, 19-year-old country singer and ruining her big moment by declaring: "Yo Taylor. I'm really happy for you, I'm going to let you finish, but Beyonce had one of the best videos of all time." On another, his comments succeeded in inflaming a long-standing rivalry: between country music, a white, Middle American genre that boasts a mostly conservative audience, and the grittier urban world of hip-hop.

Even if you ignore the unsavoury suggestion, advanced in myriad news reports and internet forums, that West's comments somehow make him a traitor to the black community, there is little denying that they tarnished what is arguably America's most prestigious music award show after the Grammys.

The crowd repeatedly booed when his name was mentioned during the ceremony at New York's Radio City Music Hall, and a string of celebrity guests used the internet site Twitter to register dismay. Pop star Pink called West a "douche bag," and Kate Perry, said of his behaviour: "it's like you stepped on a kitten."

It was the latest in a series of public controversies that have dogged West since the sudden death of his mother and mentor, Donda, in November 2007. Since then, the man once pegged as the clean-cut face of bourgeois hip-hop – the first rap artist to boast a college education, and grace the cover of Time magazine – has dispensed with his longstanding fiancee and gained a reputation for combustible behaviour, including being arrested last year and charged with assaulting a paparazzi photographer at Los Angeles airport.

In an effort to repair the damage, West took to his blog to apologise for the incident, writing: "I'm sooooo sorry to Taylor Swift... I'm in the wrong for going on stage and taking away from her moment... I'm sorry to my fans if I let you guys down."