Composer Elliott Carter was still composing prolifically beyond his ninetieth birthday.

Judge as of 2004-09-05. True: Elliott Carter (born 11 December 1908) was alive and kept composing new works at a substantial pace after December 1998 up to 2004 (e.g. several new works a year listed in his catalogue for 1999–2004). Mostly true: he composed regularly after 90, but 'prolific' slightly overstates the output, or a minor detail is off. Mixed: he composed some works after 90, but the output was sparse. Mostly false: only one or two minor works after 90. False: he composed nothing after his ninetieth birthday, or was not alive or active then.

Set before the research began.

1. E1 Biography | Elliott Carter, composer Elliott Carter (composer's official website) · 1 January 2026

   “Carter composed more than sixty works after the age of ninety including his Cello Concerto (2000), Of Rewaking (2002), Dialogues (2003), Three Illusions for Orchestra (2004), Mosaic (2004), and In the Distances of Sleep (2006).”

2. E2 List of compositions by Elliott Carter - Wikipedia Wikipedia · 5 August 2016

   “Oboe Quartet, for oboe, violin, viola, and cello (2001)”

3. E3 A perfect cadence The Spectator · 26 November 2008

   “John Link, in a celebratory article published in the contemporary music journal Tempo, calculates that since he composed his first opera, the black comedy What Next?, in 1998, he has written three dozen new pieces, representing a third of his work list to date.”

4. E4 Late Bloomer | Tim Page The New York Review of Books · 18 April 2019

   “He composed steadily in his own distinctive manner from his teen years until that day in November 2012 when, at the age of 103, he simply stopped.”

E1 names works Carter wrote after age 90 and before the judging date: the Cello Concerto (2000), Of Rewaking (2002), Dialogues (2003), and Three Illusions for Orchestra and Mosaic (both 2004). E2 adds the Oboe Quartet (2001). E3 reports that he wrote about three dozen new pieces between 1998 and 2008, which is several a year. E4 confirms that he kept composing steadily until 2012, so he was alive and active in 2004. Taken together, this shows a substantial pace of new works from 1999 to 2004, which meets the criteria for true.