Lady Gaga wears her own clothes in 'A Star Is Born'

An unexpected perk of making a movie with Lady Gaga? The ability to dip into the style.

"We did not have full-blown," "A Star Is Born" costume designer Erin Benach told Fashionista.

But this is not a bad idea, but it seems to be a good idea to have a Marc Jacobs coat might have been, Benach purposefully pulled staples like jeans and leather pants instead of dramatic performance pieces.

"We worked really hard to create a character that did not have any Gaga in it," Benach told the website. "That was one of the biggest challenges of the movie. Everybody has their own ideas of what they are and they like it. Off-duty and on-duty. And on top of that, having Gaga be Gaga, we were so conscious. "

"You know what piece is Stefani Germanotta's? "The costume designer continued. "When she's [in the recording studio] and she's got a multi-colored shawl on. That was from her closet. "

The rest of Ally's wardrobe is a mix of vintage treasures, Benach's own designs and custom pieces from major fashion houses – like the gold ruffled Gucci gown Gaga's character wears to the Grammys, a last-minute addition the pop star herself insisted on wearing.

"I was driving to work that morning of the Grammys [shoot] – it was like 5:30 am – and I answer my phone, "Benach told Fashionista. "'Hi Erin, it's Stefani, I … think we should wear the dress today instead of the black dress.'"

In the world of "A Star Is Born," it seems, even the costumes are a harmonious collaboration.