Houston, Texas, covers 665 square miles, yet the amount of space where you are legally allowed to play music for tips is limited to the city's tiny Theater District. Now a musician is suing the city, claiming these busking restrictions are unconstitutional.

On Wednesday, Tony Barilla—a Houston-based musician who has recorded music for public radio's This American Life—filed a lawsuit in the U.S. Southern District Court of Texas. He argues that these limitations on his ability to busk, and the permitting hoops he has to jump through to play even there, violate the First Amendment's free speech protections.

"The second a musician asks for tips while performing, the law is triggered," says Mollie Williams, an attorney with the Pacific Legal Foundation, which is suing on behalf of Barilla. "You can panhandle, you can protest, you can actually perform and not ask for tips, and the law won't apply to you. This law is targeting speech based on its content."

Barilla has written about his Kafkaesque experience trying to obtain a busking permit, a process that required contacting multiple government officials just to get the application. He was also forced to specify where in the Theater District he would be playing music, then obtain permission from the property owners abutting that location.

"It turns out that one's ability to get a permit in Houston doesn't depend on the city at all. It depends on the whim of about a dozen business owners," Barilla wrote.

Requiring buskers to get the permission of nearby property owners is also constitutionally problematic, argues the Pacific Legal Foundation.

"Whether an applicant is able to obtain a permit and exercise his right of free speech depends on the whims of a few people, who together enjoy a 'Heckler's Veto' over that speech," the lawsuit argues. "This limitation, like all of the busking restrictions, does not apply to other speakers, like protestors or panhandlers."

The complaint also notes that it is often difficult to find the property owner whose permission is needed.

Anyone violating Houston's busking restrictions can be subject to fines as high as $500. Barilla wants the court to strike down the regulations, thus allowing him to play wherever people might want to pay him.

Williams points out that there are all kinds of less restrictive ways the city could regulate street music, including limiting the times of day people can play or requiring performers to be a certain distance from business entrances.

"When the government gets to decide what speech is allowed and not allowed based on content, that becomes a pretty scary world," she says.