The guys may have brought down the house for "American Idol's" Motown week, but it was the ladies who hit the high style notes March 23 with Supreme-ly glamorous looks.

Judge Jennifer Lopez, who knows a thing or two about looking diva-glam, etched an imaginary check mark in the air when Pia Toscano finished belting out a Stevie Wonder ballad in a dramatic A.B.S. black gown with a plunging, sequins trimmed back. "Image? Fabulous," Lopez shouted, as host Ryan Seacrest twirled Toscano around to show the full effect.

The high sartorial praise was not lost on the show's ladies costume designer, Emmy-winner Soyon An, who had picked the dress with Toscano in mind several weeks ago and had it waiting in the wings for the right night. "The ladies from that era were super diva and I wanted to bring on the elegance for the Motown theme. I'm glad everyone loved the look as much as I did."

An shared some behind-the-seams dish on the ladies stage looks exclusively with StyleList:


Haley Reinhart: The husky-voiced performer amped up her performance --which the judges called one of her best-- in sexy, black short shorts paired with a custom-tailored Zara jacket and Marciano vest sewn into its lining for a flawless fit. Hand-sewn rhinestone buttons and a lone cameo were added "to make it more personal." While the Motown sound was the inspiration, so were Reinhart's long legs which rocked towering bow-detailed Marciano shoes. Stacks of bangles were used to cinch her cuffs. "She's a sexy tomboy and I loved bringing in the masculine look with a feminine twist."

Lauren Alaina: Wore her first dress of the season, a strapless floor-length animal print with a splash of neon pink at the hem paired with fringe, crystal earrings by Martin Wester. The funky frock was a one-of-a-kind "no label" find from The Mint Collection in Los Angeles.


Thia Megia: The 16-year-old wore a flirty, two-tone short strapless dress with a tiered, ruffle skirt by Lipsy paired with massive, a one-of-a-kind jewel-encrusted heart pendant by Tarina Tarantino to step out of the ballad zone. An wanted to keep Megia looking age-appropriate, "but also she is also an old soul, so balancing the two things is keeping my job interesting."

Naima Adedapo: An, who is also lead costume designer for Fox's "So You Think You Can Dance," used her knowledge of dance apparel to create a custom midriff-baring top for Adedapo, which took more than 20 hours just to pleat. The singer, who added a kinetic African-inspired dance routine to her performance of "Dancing in the Streets," also wore more than 20 Catherine Michiels wrap bracelets and a pair of dramatic, flared-pants from the Los Angeles boutique Church.

For more reality style, read about what the contestants wore for this week's premiere performance of "Dancing with the Stars."