iHeartRadio Festival 2013 Red Carpet: Katy Perry, Miley Cyrus + More [PHOTOS]

Pop stars and more congregated at the IHeart Radio Festival in Las Vegas this weekend, looking wild and crazy in their ensembles. It's a live festival, so attire was loose and casual (unless you were Diddy), and they were able to push the boundaries of fashion. Like Katy Perry, who had strange bun-like appendages sitting atop her head, did. Meanwhile, Miley Cyrus paired a revealing, bathing suit-like stage outfit with sneakers.

She also went Gaga -- literally -- with her white mesh/netted "dress" over black pasties and dominatrix-like undies.

See our recap of red carpet walkers and their cray cray ensembles.

Katy Perry rocked Princess Lea buns + strappy heels.

Can she communicate with life on other planets via those buns?

The man in black ... Robin Thicke. Is a single hair out of place? Nope.

A hybrid of dominatrix beachwear for Miley. Risque and anything but modest.

Miley really took the plunge.

Cher Lloyd was a golden goddess with those kicks.

Diddy classed things up in a tux.

Avril Lavigne put on her war paint and really big platform boots. What's with the fur sleeves in Vegas, too?

Kelly Rowland's boots were made for walking and they meant business.

Breezy cracked a smile during an interview.

The ladies of TLC once ruled this roost! They're still hot, especially in leather.

Check out Jason Derulo in that custom sliced Nirvana tee.