A copyright infringement lawsuit filed earlier this year by the estate of the composer of “Over the Rainbow” against some of the biggest tech companies now has two new traveling companions on the yellow brick road.

The estate of Harold Arlen and his son, Sam, sued Apple, Amazon, Google, Microsoft and others in May for what they claim is a “massive piracy operation for the purpose of generating profits from their sales and streams of pirated recordings.” That suit has been joined by heirs of songwriters Harry Warren and Ray Henderson. The additional named plaintiffs in the amended complaint are Four Jays Music Company, founded by Warren in 1955, and Ray Henderson Music Co., Inc.

The initial complaint alleged there were over 6,000 unauthorized recordings of Arlen’s music for sale on the companies’ main platforms and international distribution outlets. With the addition of the Warren and Henderson heirs, the amended complaint has increased that number to more than 9,000 infringing recordings, according to a press release from plaintiffs attorney Matthew F. Schwartz of Schwartz, Ponterio & Levenson.

The complaint now lists 307 claims of copyright infringement against the aforementioned companies, which includes over 60 smaller companies and record labels.

The suit provides examples of unauthorized versions, noting that the album cover art for these recordings were doctored to remove the record label logos. The suit alleges that these pirated recordings are being sold side by side with legitimate albums, and often for less money.

“The case confirms that music piracy continues to be a serious problem,” said Schwartz in the press release. “This new filing joining the works of Harold Arlen with those of Harry Warren and Ray Henderson demonstrates that the case is gaining momentum as more songwriters and music publishers realize the scope of the problem and what is at stake.”

The plaintiffs may seek up to $150,000 in statutory damages for each infringement award, says Schwartz.

Apple, Amazon, Google, and Microsoft have not responded to requests for comments at press time.

Harold Arlen wrote music for 13 Broadway musicals, in addition to writing songs for The Wizard of Oz. He composed several hit songs throughout the 1940s and 1950s, including “Stormy Weather,” “Blues in the Night,” “Come Rain or Come Shine,” and “The Man That Got Away,” made famous by Judy Garland in the 1954 version of A Star is Born.

Harry Warren’s songs were featured in more than 300 films. He was nominated for an Academy Award eleven times, winning three Oscars for Best Song. Those songs were “On the Atchison, Topeka, and the Santa Fe“ from The Harvey Girls, ”You’ll Never Know” from Hello, Frisco, Hello, and “Lullaby of Broadway” from Gold Diggers of 1935.  Warren wrote over 800 songs, including “Chattanooga Choo Choo,” which became the first song to receive a gold record for sales of 1.2 million copies.

Ray Henderson was part of the most successful songwriting team of the late 1920s and 1930s with Lew Brown and Buddy DeSylva. His works include “Bye Bye Blackbird,” “The Best Things in Life Are Free,” and “Life is Just a Bowl of Cherries.” Henderson was selected for the inaugural induction into the Songwriters Hall of Fame in 1970.

Read the amended complaint: