Katy Perry wore:

Jumpsuit:  Moschino Cheap & Chic S/S 12 pre-collection

Jewelry:  Jennifer Fisher ring, 14K yellow gold Cigar band w/medium Pave Black Diamond Gothic Letter "K"

She was styled by Johnny Wujeck.

Katy Perry wore:

Dress:  Zac Posen

Shoes:  Casadei

Clutch:  Judith Leiber

Earrings:  Dijan from Lebanon

She was styled by Johnny Wujeck.

Kristen Bell wore a dress from 3.1 Philip Lim paired with Jimmy Choo "Katy" platforms .  She carried a clutch from Topshop.  Earrings were from Amrapali and chocolate diamond ring was from LeVian.

She was styled by Nicole Chavez.

Olivia Wilde wore a dress from J. Mendel with Jimmy Choo "Lottie" sandals.  She carried a Sergio Rossi clutch.  Her earrings were from Sara Weinstock and ring & bangles were from Arman.

She was styled by Kemal & Karla.

Ashley Greene wore a dress from BCBG Max Azria with a Sergio Rossi clutch & shoes.  Her jewelry was from Loree Rodkin.

She was styled by Ilaria Urbinati.

Amber Heard wore a top and skirt from Alexander Wang, with a belt from 3.1 Philip Lim.  Her shoes were from Chloe.  She carried a clutch from Stella McCartney.

She was styled by Johnny Wujeck.

Amanda Bynes wore a dress from Pencey with Louboutins.  Her clutch was from Tory Burch and necklace from Roberto Coin.  She did not work with a stylist.

Leona Lewis wore a woll cocktail dress with silk georgette sleevs from Elie Saab.  She did not work with a stylist for this event.

Marion Cotillard selected an Elie Saab mosaic print silk dress from the RTW Fall 09 collection.  Her python clutch was also from the Elie Saab collection.  Her shoes were Jimmy choo "Gloss" platform sandals.  She did not work with a stylist for this event.

Christian Bale wore a head-to-toe YSL ensemble.

Leelee Sobieski selected an Hermes dress for the occasion, topped with a Donna Karan leather jacket.  Shoes were from Azzedine Alaia.  Her belt was from her own collection - purchased at a vintage store in Santa Fe.  She did not work with a stylist for this event.

Amber Heard wore a dress and belt from Eva Culture with Jimmy Choo "Idol" platforms.  She wore a spiked ring of black and white diamonds from Hellmuth and a cocktail ring in chocolate diamonds from Le Vian.  Her black diamond cuff was from Bochic, and pink diamond and platinum cuff was from Neil Lane.  She was styled by Johnny Wujeck.

Rosario Dawson wore a dress from Dries van Noten.

PHOTOS COURTESEY OF ELEVATION PHOTOS.

MTV Japan also held an awards show this weekend, and American music stars appeared and performed.

Ciara brilliantly paid her respects to Japanese fashion with a leather dress and bracelet from Tokyo-based brand Dresscamp, which she paired with Louboutins.

Fergie wore a Marc Jacobs dress with Louboutin heels.

On stage, Fergie wore a custom piece from Marcomarco and Thai nails painted in silver and black. She was styled by Laura Lightbody.

Katy Perry wore a dress from Indian designer Manish Arora (though he currently shows in Paris).  She is styled by Johnny Wujeck.

Katy Perry is wearing a dress by Basil Soda, shoes from Christian Louboutin, bracelets and ring by H. Stern and earrings from Jacob & Co.  Katy is styled by Johnny Wujeck.

Katy's performance dress will be from Jenny Packham. Pics TK!

Taylor Swift wore a sparkly Collette Dinnigan with Louboutin peep-toe heels and carried a Jimmy Choo clutch.  Jewelry was from Lorraine Schwartz.  Taylor is styled by Joseph Cassell.

Whitney Houston wore Dolce & Gabbana to perform at Clive Davis' annual pre-Grammy party.  Whitney is styled by Timothy Snell.

Rihanna wore a dress by Roberto Cavalli.  Jewelry was yellow gold Croco cuffs and a gold & diamond ring from Hellmuth. 

Katy Perry wore a Georges Chakra dress with Louboutins and a clutch from Renee Caovilla.  Earrings were from H. Stern and ring was Zorab.  Katy is styled by Johnny Wujeck.

Miley Cyrus wore a Cavalli dress, BCBG shoes, earrings by Bochic and a ring from Amrapali.  Miley was styled by Tara Swennen.

Jennifer Hudson (pictured with Clive Davis) wore a Todd Lynn dress with a Balenciaga bag, Ferragamo shoes and jewelry by Loree Rodkin to Clive Davis' annual pre-Grammy party.  Jennifer is styled by Lisa Michelle Boyd.

Keyshia Cole wore a dress by Grai, shoes from Givenchy, clutch from Swarovski and jewels from H. Stern.

Estelle wore a Fendi top with leggings by American Apparel.  Shoes were from Halston, clutch Calvin Klein and jewelry from Noir.

Sheryl Crow wore a dress from Ports 1961 with a bag from Mary Norton, jewelry from Pratt Vintage Jewelers, with Sheryl's own shoes.  Sheryl is styled by Wendi + Nicole.

American Idol judge Kara DioGuardi wore a Nicole Miller gown to the event.