Burbank Show Choirs spent about $100K on costumes last year but didn’t pay a dime to license the music they used, according to the lawsuit.

The real-life show choir that inspired William McKinley High's New Directions on Glee hasn't paid a cent to license the music it uses, according to a lawsuit filed Wednesday in California federal court.

Burbank Show Choirs has performed 89 hits ranging from Katy Perry's "California Gurls" to Frozen's "Let It Go" that weren't properly licensed, the suit claims. So Tresona Multimedia is suing Burbank High School Vocal Music Association and its board members for copyright infringement.

Tresona says it issues copyright licenses to bands, choirs and other organizations on behalf of all major music publishing companies through its proprietary online licensing exchange, and Burbank Show Choirs isn't one of its customers. The company claims it is the only authorized issuer, other than the publishers, for 79 of the songs and has a permissive but non-exclusive right to issue licenses for the other 10.

“The Burbank Show Choirs are some of the most prominent show choirs in the country," states the complaint. "In fact, it is widely understood in the industry that the television show ‘Glee’ was based upon the Burbank Show Choirs, with input from Defendant Brett Carroll.”

The group's fame makes its performances highly lucrative. Despite having revenues and expenses in the “mid-six figures” each year, Tresona claims the group has refused to pay for copyright licenses. To legally perform their shows, Tresona says the show choirs would need a custom arrangement license, grand right license and mechanical license for each song the group uses — plus a synchronization license if they intend to create an audio-visual recording of the performance.

"None of the Defendants has ever paid any songwriter or rights holder a single dollar for the custom arrangements that Defendants created, commissioned, recorded and disseminated related to the Burbank Show Choirs," states the complaint.

Tresona also claims the real-life equivalent of Will Schuester knows what his group is doing is illegal and has ignored repeated warnings.

"The infringement in which Mr. Carroll has been involved is egregious and willful," states the complaint. "He has knowingly given advice to others urging them to violate copyright law."

The Burbank High School principal refused to purchase the licenses, according to the complaint, and an assistant superintendent said in a meeting that it was "an embarrassment" that he would rectify, but upon receiving the bill the school "'lawyered up' and refused to pay anything."

From 2010 to 2015 the group paid music arranger Josh Greene to duplicate audio recordings of his arrangements, but Tresona claims after he became aware of the infringement he stopped working with the school and the show choir found a different arranger — one whose name is kept a secret.

Tresona is seeking statutory damages of up to $150,000 per infringement, plus compensatory and punitive damages and a permanent injunction.

School officials have not yet responded to a request for comment.