- Justin Bieber wins four awards including Favourite Artist
- Katy Perry, Fergie and Christina Aguilera put on racy performances
Perhaps in a bid to steal Madonna's crown as the queen of reinvention, Rihanna has debuted yet another new style.
The singer arrived at the American Music Awards last night sporting an Eighties' style perm in her flame-coloured hair.
Rihanna maintained her provocative fashion sense in a revealing backless Elie Saab gown, before changing into another risqué onstage outfit at Los Angeles' Nokia Theatre.
Dynamic: Rihanna captivated the audience at the 38th AMA awards tonight as she opened the show with a medley of songs from her album Loud.
Moving to the beat of her own drum: Rihanna performed a medley of her hits at the American Music Awards in Los Angeles tonight
The 21-year-old wore an eye catching black and white cropped top, with a multi-coloured shawl over some black hot pants as she performed a medley of songs from some of this year's hit songs.
She opened the awards show perched atop a tree singing an a cappella version of Love The Way You Lie Part 2 wearing a demure blush-coloured sheath.
She then 'tumbled' from her perch in spectacular fashion into a plume of fog before emerging in her colourful costume to move into an energetic performance of What's My Name followed by Only Girl in the World.
She ended the performance with flames shooting skywards while she returned to her perch in the tree to receive a rousing standing ovation from the audience.
Demure to diva: Rihanna perched in the air before writhing into an energetic performance.
Opening Act: The singer performed a medley of her hit singles What's My Name, Only Girl in the World and Love The Way You Lie
Earlier in the evening Rihanna dazzled on the red carpet in a revealing backless gown by Elie Saab which featured lace embroidery over delicate sheer material.
She changed into a more demure green one sleeve gown, also by Elie Saab, to collect the gong for Favourite Soul/R & B Female, where she declared: 'This is amazing!'
In recent weeks The Barbadian artist has tried out extensions, waves and a cropped style in her bright red hair, which she has sported for a few months.
Past hairstyles have included a long straight hair, a blunt bob, a cropped quiff and a shaved undercut.
Provocative: Rihanna wowed on the red carpet in a see-through backless gown by Elie Saab
The chart topper has been raising eyebrows of late for her sexually charged antics, including a racy photoshoot for her album which included suggestive half-naked pictures of the star.
Rihanna had some competition on the night from the likes of Christina Aguilera, Fergie and Katy Perry, who also donned a variety of stunning outfits as they performed a series of show stopping numbers.
Christina Aguilera wore a black basque, black fishnet tights and high heeled black lace up boots for a stunning rendition of her new song (Express) Burlesque.
Showgirl: Christina Aguilera wore black basque, high heeled lace up boots and fishnet tights for her performance of (Express) Burlesque at tonight's AMAs 
Showstopper: The singer performed the dramatic number on a set designed to look like backstage at a Burlesque club
The singer performed with an array of dancers on a set designed to mimic the design of a Burlesque club.
Katy Perry took to the stage after descending from a star to perform Firework - the latest single from her platinum selling album Teenage Dream.
Wearing a sparkly red catsuit, the newly married Mrs Russell Brand sang in front of a slew of fireworks, ending her performance with her backing dancers lifting her into the air.
The star had earlier stepped out on to the red carpet wearing a strapless pink dress.
Fergie also made her mark during her performance with the Black Eyed Peas for their dramatic dance number (This Time) The Dirty Bit.
Wearing a multi-coloured dress, complete with wire skirt, the star joined her band mates to collect the award for Favourite Band, Duo or Group.
Singer will.i.am ensured he used their acceptance speech to plug their forthcoming album The Beginning, which comes out November 30.
The show proved to be full of memorable performances with Miley Cyrus taking to the stage in a gothic themed number where she performed ballad Love & Forgiveness wearing a flowing black gown.
And Taylor Swift cemented the best selling performance of her latest album Speak Now with a rendition of the album's ballad Back to December.
She had earlier collected the award for Favourite Female Country Artist for the third consecutive year in a row.
High lift: Perry ended her performance when she was lifted up by her make backing dancers
only want to thank the fans,' she said. 'You get me and you know where I'm coming from. Thanks for giving me so much love for the new album.'
A pregnant Pink was also among the evening's performance highlights.
Unlike recent performances marked by a high-wire act, she stayed close to the ground to perform her latest song, Raise Your Glass, but thrilled nonetheless with a tightly choreographed, high-energy dance number.
Rainbow bright: Fergie wears a low cut multi-coloured dress with a wired skirt during the Black Eyed Peas performance of their new single
Ke$ha, perhaps trying to make up for the absent Lady Gaga, had the night's most bizarre performance: she performed her heavily Auto-Tuned hit Take It Off looking like something out of space, with beams of light for eyes and sporting a motorcycle helmet.
She then stripped down to a mirrored outfit, segueing into the next song with a pack of male dancers dressed like her, complete with blond wigs and fishnet stockings.
But it was Justin Bieber who swept the board, capturing every award he was nominated for.
Stop the haters: Kesha performed her heavily Auto-Tuned hit Take It Off
Young talent: Miley Cyrus performs ballad Forgiveness and Love in a long black gown, while award winner Taylor Swift sang Back to December, a number from her hit Speak Now album
The 16-year-old teen heartthrob, who will perform in the UK on next week's X Factor, went four-for-four, including the top award of the night, Favourite Artist.
He beat a list that featured veterans Eminem and Usher as well as Perry and Lady Gaga.
Bieber became the youngest person to ever win the trophy.
Bieber also won Favourite Pop/Rock album, Favourite Pop/Rock Male, and the show's Breakthrough Artist award.
Tickling the ivories: Justin Bieber performed the ballad Pray before winning four awards, including favourite artist
'I can't stop smiling; this is amazing,' Bieber said after he also beat Eminem and Usher for favorite pop/rock male.
'Truly I don't know how this is possible because I've been singing Eminem since I was three and Usher is my mentor. So this is big.'
Eminem, along with Lady Antebellum, had been the leading nominee with five awards.
He didn't come up empty handed though, winning two, along with Usher, who also nabbed a pair. Lady Antebellum took home one.
Collaboration: New Kids on The Block and Backstreet Boys closed the show with a medley of their greatest hits including Hangin' Tough and I Want It That Way
The show was closed with a collaboration between 1990s boy bands New Kids On The Block and the Backstreet Boys.
They performed a medley of their hits including Everybody (Backstreet's Back) and the classic number one hit Hangin' Tough.
The two groups also sang Backstreet song I Want It That Way and New Kids number Step By Step before confetti fell and the show ended.
