In brief: The creators of the original music used on the Halo games developed by Bungie are suing Microsoft over unpaid royalties dating back to the original game's release. If both parties can't reach an agreement, the case may go to court, but even worse is that the Halo TV show may get canceled with a preliminary injunction.

Marty O'Donnell and Mike Salvatori are the minds behind Halo's iconic soundtrack, including the "monk" chant and the "der der der der" refrain. Their work is well known in the Halo community and have been used in various Halo products. However, the composers affirm Microsoft is misusing them by not paying royalties they're due for 20 years.

Both composers claim Bungie licensed the music for the first three Halo games. However, the Redmont-based company acquired the studio in 2001. Back then, O'Donnell was still the audio director at Bungie, while Salvatori worked for the developer as an independent contractor, working for the O'Donnell Salvatori Inc. (Salvatori also worked there).

The composers tried to discuss the matter with Microsoft before formally accusing the company. On one side, Microsoft claims the music team created the Halo music under a work-for-hire agreement, which makes the tech giant the author of the work under the eyes of the law. On the other, the composers stated it was always a licensing deal.

Despite the lawsuit, O'Donnell and Salvatori aren't trying to claim credit for the music piece. Instead, they are charging Microsoft for not paying 20 years' worth of royalties. In summary, they're accusing the tech giant of breach of contract, breach of fiduciary duty to develop the royalty income in a joint venture, breach of duty to act in good faith and fair dealing, failure to provide an accounting partnership, unjust enrichment, and tortious interference.

Both parties have a mediation scheduled for next week, where they will try to reach an agreement. If they fail, the case might go to court.

In addition, the composers are planning to instruct lawyers to explore the possibility of blocking the debut of the Halo TV show via a preliminary injunction. The 10-episode series, scheduled to launch on Paramount+ March 24, might be delayed or canceled.