The creators of Halo's famed soundtrack, which includes the famous monk chant' theme, are suing Microsoft for unpaid royalties dating back 20 years.

The Halo soundtrack, particularly the classic main theme, is one of the most recognisable in all video games. The Halo theme, which began with an operatic choir-like chant, has been modified and covered by anything from marching bands to echoing stairwells and has appeared in every numbered mainstream Halo game.

Bungie created the first Halo game, Halo: Combat Evolved, which was released as a launch title for the original Xbox in 2001. Its success established the game's status as not only an iconic game (as evidenced by all the titles that tried to cash in on Halo's success) but also as Xbox's flagship series. The Halo franchise is so closely associated with Xbox that Microsoft named its virtual assistant Cortana after the game's AI companion.

The original composers of Halo's music are suing Microsoft, saying they have entitled royalties for the game's entire 20-year lifespan. Marty O'Donnell and Mike Salvatori, two composers, launched the action in June 2020, with no settlement in sight. If no settlements are reached within the next week, the case may be taken to court.

Although the soundtrack is now inextricably tied with Halo's release on the first Xbox, it was not the first time it was played. Originally, Halo was a game being created by Bungie for the Apple Mac computer, and it was originally shown off at the 1999 MacWorld event in a very early version. At the event, a concept trailer was shown, with the legendary Halo theme playing in the backdrop. Bungie, which was recently acquired by Sony, was first purchased by Microsoft in 2000, after which the Apple project was shelved and Halo was reimagined as the Xbox franchise it is today.

The work done for Bungie in 1999, according to O'Donnell and Salavtori, was a licenced deal that gave the composers the opportunity to claim income on their music if it was used in future projects. Microsoft contests this allegation, claiming that the music was work-for-hire and that when Microsoft bought Bungie, it also bought the soundtrack's authorship.

Over the last two decades, the Halo soundtrack has been used in a variety of projects, including not only Halo video games but also promotional material and spinoffs. Even a sting from the game's soundtrack appears in the trailer for the new Halo TV programme on Paramount+, implying that some legendary tracks may feature in full in specific episodes. Microsoft is unlikely to entertain the idea of paying all royalties for these uses, as well as every future usage of the music it has freely utilised up to this point. However, after nearly a year of litigation with no settlements, it may be considering fighting the lawsuit rather than buying the licence outright, whether perceived or not.