Taylor Swift parades her long legs in purple sequined romper while Katy Perry rocks retro plaid number on the iHeartRadio Awards 2019 red carpet

It's one awards show where anything goes. And Taylor Swift and Katy Perry took this is very different ways, as the two stars showed off their unique approaches to fashion at Thursday night's iHeartRadio Awards. 

For Taylor, it was a chance to make a splash showing off her long lean legs in an iridescent purple romper with mermaid-like allure. Meanwhile Katy went in a completely different direction. The retro-loving star put a shiny spin on vintage vibes while wearing a black and white shirt dress with a clear plastic layer on the outside.

Taylor's piece, which was designed by Rose Bloom, let the star parade her thin stems. She elevated her look with metallic Sophia Webster heels which featured butterflies off the back.

Drop earrings from State Property dangled from each lobe and she stacked rings for an bit of extra flash. The Delicate songstress teamed her leggy look with sassy cat-eyes, fluttering lashes and a pop of pink lipstick.

There was no denying Katy's retro appeal. Her collared frock was unbuttoned just enough to reveal a blue bra beneath while highlighting her hourglass figure with a thick belt in the center. She added a pair of patent leather driving gloves and black Mary Janes with white socks for accessories. Continuing her retro look, she wore her hair in a platinum bob curled under à la 50s housewife and swept out of her face with a shiny headband. Cherry red lips and round earrings completed her look.

Her date for the evening was not fiance Orlando Bloom, but rather DJ/collaborator Zedd. Before Taylor and Katy's arrivals, Halsey lead the red carpet in a fashion-forward outfit of black pants and white shirt, with a black bow tie. Also seen on the red carpet was her boyfriend Yungblood, although the two did not pose up together. They did, however, take a flirty interview together.

Elle Fanning stunned in a soft nude gown which was embellished with rhinestones across a cross-crossing bodice which flashed her sides. She continued to sparkle with a collection of diamond bangles on her wrist. The actress, who has been promoting her musical drama Teen Spirit as of late, styled her hair smoothly and plumped up her pout with the help of some extra liner.

Country singer Kacey Musgraves was also an early arrival, in her sculptural black and gold David Koma dress. The 30-year-old, who is up for Best Cover Song, wore her black hair loose over her shoulders, as she posed in her short gown. Bebe Rexha went for matador-like appear donning a wide-brimmed hat with a sexy suit. She played up her eyes with smoky shadow.

YouTube star Madison Beer, a protege of Justin Bieber, wore a plunging strapless gown with Grecian influences. The 20-year-old showed off her slender legs in the outfit as she posed, smiling for the cameras. Heidi Klum was a daring fashionista donning an A-line leopard look with silky, knee-high boots. She styled her hair with blunt fringe while going with a bronze eye for her beauty. The former America's Got Talent hostess put on a playful display, spinning around to let her sheer style swing around her thin frame.

Also attending was Marren Morris, who flaunted her figure in a tight triangle-patterned dress. Steven Tyler showed up with his girlfriend Aimee Preston, who is 40 years his junior. The Aerosmith rocker was stylish in a pair of paisley-studded pants with a long cardigan on top while his other half sparkled in a silver sequin jumpsuit. While posing the pair shared a kiss. It is shaping up to be a huge night as Taylor Swift is expected to be making an appearance as she was already named winner of the Tour of the Year Award for her Reputation Stadium Tour.

The 2018 tour became the highest-grossing tour by a woman as it sold two million tickets in the US with $266 in sales. Ariana Grande will also be performing and is nominated for five awards. Her adorable pet pig Piggy Smallz is also up for an award in the social media voted Cutest Musician Pet category. Coming off of her incredible job in hosting The Grammys last month, Alicia Keys will not only be performing at the event but also be recognized for her trailblazing in the music industry.

The 38-year-old will be receiving the iHeartRadio Innovator Award for her contributions to pop culture and social causes as an artist, songwriter, producer, entrepreneur, and activist. She joins esteemed company including Bruno Mars, Pharrell Williams, U2, Justin Timberlake, and Chance the Rapper. Garth Brooks will also be honored as the first ever recipient of the Artist of the Decade Award. The 57-year-old musician is the number-one selling solo artist in US history and is also set to hit the stage for a performance. Halsey will also hit the stage as she will also be receiving the Fangirls Award presented by L'Oreal Paris which recognizes a female artist who has pushed boundaries with her music and message while inspiring her fans.

Camila Cabello was the inaugural winner of the award last year. Other performers include Kacey Musgraves, Backstreet Boys, John Legend, Ella Mai, Marshmello and Travis Barker. Masked Singer winner T-Pain is hosting the event, arriving in a suitably loud, bright orange suit.