 For Halo Wars , the task of creating the game 's music fell to Stephen Rippy . Rippy listened to O 'Donnell 's soundtracks for inspiration and incorporated the Halo theme into parts of his arrangements . In addition to synthesized and orchestral components , the composer focused on the choir and piano as essential elements , feeling these were important in creating the " Halo sound " . Rather than use the Northwest Sinfonia , Rippy traveled to Prague and recorded with the FILMharmonic Orchestra before returning to the United States to complete the music . A standalone compact disc and digital download retail version of the soundtrack was announced in January 2009 for release on February 17 . 
