Strachan wrote the internationally recognised quiz show’s theme - actually 95 different pieces of music covering any eventuality on the programme - with his father Keith.
“Matthew was loved by his family and he will be sadly missed,” Keith Strachan told BBC News.
Strachan was reported to have died suddenly at his house in Twickenham, in west London, some weeks ago. Police have said his death is not being treated as suspicious.
The West London Coroner opened an investigation into the death 15 days ago on 8 September, reported the Daily Mail. Following a post mortem, the coroner’s office is now awaiting toxicology and histology results to help determine the cause of death.
The composer was charged with one count of arson earlier this year, reported the BBC.
Composer Daniel Pemberton remembered Strachan on Twitter as “someone who chased a magical dream” and continued to make “funky” music under his alter ego, a fictional music composer of 1970s European adult films known as Klaus Harmony.
Artist manager Sean Devine wrote on social media that Strachan was “fun to work with and a joy to be around”.
Theatre director Andrew Keates said he would miss his “talented friend” Strachan who wrote all the music for Keates’ plays. “Silence is ringing in my ears,” he said.
And the writer Dirk Maggs, who paid tribute to Strachan on 16 September, said his friend was “gentle, kind, talented and wickedly funny”.
In a 2014 interview with BBC Radio One London, Strachan recounted the circumstances under which he wrote the score for the quiz show, which has many international versions, but first began in Britain.
Part of a team put together to overhaul the unsuccessful non-broadcast pilot of Who Wants To Be A Millionaire, Strachan and his father decided to create 95 pieces of music ”to cover every eventuality of what happens in the show”.
The Strachans completed the task over an eight-day period in 1998, after which they went on to win the American Society of Composers, Authors and Publishers’ award for the the most-broadcast piece of music on US TV for their work for 10 years in a row.
Strachan’s other works included writing the music for BBC Radio 4’s First World War drama series Home Front and some of Jasper Carrott’s BBC comedy shows.
His work also appeared in films like Slumdog Millionaire, Extract and About A Boy.
He is survived by his wife, the author Bernadette Strachan, and their daughter Niamh.
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