The Wizard of Oz (1939). (Courtesy of Metro-Goldwyn-Mayer)

The estate of Harold Arlen, the composer of “Over the Rainbow” and other classic songs, has dropped a house on the biggest tech companies in the form of a lawsuit over unauthorized recordings.

The Arlen estate and the composer’s son, Sam, are suing Apple, Amazon, Google, Microsoft and Pandora for what they claim is a “massive piracy operation for the purpose of generating profits from their sales and streams of pirated recordings,” reports Billboard. The plaintiffs’ attorneys say they have found over 6,000 unauthorized recordings for sale on the companies’ main platforms as well as their international distribution outlets. These recordings are being sold side by side with legitimate albums, they allege, and often for less money.

The suit provides examples of unauthorized versions, noting that the album cover art for these recordings were doctored to remove the record label logos. Arlen’s lawyers accuse the online retailers of knowingly participating with these pirate labels in infringing on the composer’s trademark.

Sam Arlen says he’s the sole statutory heir and therefore the rightful holder of his father’s copyright. The estate’s legal representatives are seeking damages as well as a halt to the infringing activity. According to Forbes, the total bill from all defendants could reach $4.2 million.

None of the defendants responded to Billboard’s request for comment at press time.

Harold Arlen wrote music for 13 Broadway musicals, including Jamaica, St. Louis Woman and House of Flowers. In addition to writing songs for The Wizard of Oz, Arlen 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.