Composer John Williams, who has scored all but two of Steven Spielberg’s feature films over the past 43 years, will not be doing the music chores on Spielberg’s “Ready Player One” — instead, that job will go to “Forrest Gump” composer Alan Silvestri.

Because post-production is happening on the same time on both “Ready Player One” and Spielberg’s other film, “The Papers,” Williams will score the latter film. It will mark their 28th feature collaboration.

According to a statement from Spielberg’s Amblin Productions: “Steven and John decided Alan Silvestri was the perfect choice for ‘Ready Player One’ since Steven has worked (as a producer) with Alan on the ‘Back to the Future’ films in the ’80s and Alan has scored other films for Steven’s Amblin and DreamWorks.”

“The Papers” opens Dec. 22 and “Ready Player One” opens March 30, 2018.

Williams has done all of Spielberg’s other films except “The Color Purple” in 1985 (that went to Quincy Jones) and “Bridge of Spies” in 2015 (Thomas Newman). Three of Williams’ five Academy Awards are for Spielberg scores (“Jaws,” “E.T.” and “Schindler’s List”).