Composer

"The Composer! So many possibilities and capabilities tied up in that strange name... A Composer of minds and souls!"

- Forthencho, Lord of Admirals

The Composer was a mysterious entity, possibly a Forerunner or a Forerunner machine, that had many capabilities, including the ability to extract the consciousness and memories of a sapient being. The Librarian employed the Composer when extracting the memories of the surviving human warriors after the Charum Hakkor campaign. The Lord of Admirals, supreme commander of all human forces and one of the humans to have their minds harvested, never saw the Composer directly and described its presence as "strange, ever-changing" and "multiformed", as it operated via Lifeworker machinery.

The Composer was also capable of slowing down Flood infection and the subsequent loss of individuality. Some believed the Composer to be a "product of its own services"; a Forerunner, perhaps a Lifeworker, suspended in the final stages of Flood infection. According to Lifeworker Genemender Folder of Fortune, the Composer had once been "designed to save us all", which may have been referring to its ability to keep Flood infection in check.

The Composer, or at least its handiwork, was present on Installation 07 around 100,000 BCE, where it was used by the Master Builder to stave off Flood infection in certain Forerunners to keep them in a docile state. This was accomplished through a form of harness which prevented the infectees' decaying bodies from breaking down. By that time, the Composer appeared to be a closely-guarded secret known only to few, as a Lifeworker monitor on Installation 07 did not have any information pertaining to it in its memory.

Trivia
The achievement for completing the seventh level in the Halo 4 campaign is called "Composer". This may suggest that the Composer appears in some form in the game.

List of appearances

 * The Forerunner Saga
 * Halo: Primordium