O'Donnell and Salvatori's music has been packaged and released in physical and digital forms. The soundtracks feature "frozen" arrangements that represent an approximation of a play-through of the games. The "Halo Original Soundtrack" sold over 40,000 copies, and was followed by two different releases of the music to "Halo 2". The two volumes of the "Halo 2 Original Soundtrack" were produced by Nile Rodgers, with the first album being released in sync with the video game in 2004 and became the best-selling game soundtrack of all time. The second album was released more than a year after the soundtrack had been mixed and mastered. "Halo 3"s soundtrack was released in November 2007, and featured a fan contribution that was the select winner from a pool of entries judged by O'Donnell, Rodgers, and others. All of Salvatori's contemporary work on the series was repackaged as "Halo Trilogy—The Complete Original Soundtracks" in December 2008, alongside preview tracks written by "Halo Wars" composer Stephen Rippy. The music for "ODST" was released in a two-disc set on September 22, 2009.