Passage: Danny Elfman began composing the score in January 2009. Beforehand, McG wanted to hire Gustavo Santaolalla to work on the music for the human characters, while having either Thom Yorke or Jonny Greenwood for Skynet's themes. He wanted to discuss scoring the film with Hans Zimmer but he was unable to arrange a meeting. McG met with the original Terminator composer Brad Fiedel but was not interested in repeating the sounds Fiedel achieved in his films. However, McG wanted Elfman to give those themes and ambient sounds a "Wagnerian quality".Reprise Records released the soundtrack on May 19, 2009, which included 15 tracks. While Common had expressed interest in writing a song for the soundtrack, Alice in Chains' "Rooster" is the only featured song. Although not included in the soundtrack, "You Could Be Mine" by Guns N' Roses, which was featured in Terminator 2: Judgment Day, can be heard briefly in a scene of the film as well.

Question: When did the author of the score start composing it?
January 2009