Acclaimed composer Sir Harrison Birtwistle has died at the age of 87, his publisher has confirmed.
He is perhaps best known for 1972 orchestral work The Triumph of Time, as well as operas The Mask Of Orpheus, Gawain and The Minotaur.
Publishers Boosey & Hawkes and agency Rayfield Allied announced with "deep sadness" that he died at his home in Mere, Wiltshire on 18 April.
The Royal Philharmonic Society called him "a true musical colossus".
His friend and collaborator Martyn Brabbins, music director at English National Opera, told BBC Radio 4's Today programme Sir Harrison had an "amazing level of detail" and "everything he did had an overarching sense of dramatic impulse, of characterisation and colour".
He agreed that "complex and uncompromising" were also ways of describing his work, but that it was always governed by "a massively sincere need to communicate what music can express".
"He reached a massive audience," he said, adding: "If you got Harry's music, it was an irresistible force".
When asked about criticisms of Sir Harrison's work, such as the piece Panic from the Last Night of the Proms in 1995, which was described by some newspapers as "a cacophony", Brabbins said he "cared passionately".
Panic was the first piece of contemporary music ever to have appeared on a Last Night programme, and Brabbins said the "furore over that piece really affected Harry in a negative way".
"He was a very sensitive soul although he had a gruff exterior, he was a very creative artist," he added.
His music has featured in major festivals and concert series in Europe, the US and Japan, attracting international conductors including Daniel Barenboim and Sir Simon Rattle.
The Triumph of Time was commissioned and first performed by the Royal Philharmonic Orchestra in 1972, and is based on a painting by 16th Century Flemish artist, Pieter Bruegel, which depicts Time riding in a cart surrounded by skeletons.
The Royal Philharmonic added he had won five of its awards, and said: "His music shook the earth. There was force and potency in every note he wrote. We will listen in awe to his works for decades to come."
London Symphony Orchestra said: "Sad news to hear today that one of the greatest British composers, Harrison Birtwistle, has died."
Actor Samuel West also paid tribute.
I grew up being taken to Proms in the 80s where Harrison Birtwistle was often on the program.— Samuel West 💙💛 (@exitthelemming) April 18, 2022
His music disturbed and fascinated me. It spoke of deep, old things - a song of the earth I didn’t fully understand as a teenager. But I enjoyed trying. I’ll always be grateful for that
Sir Harrison, born in Accrington, Lancashire in 1934, studied composition and the clarinet at the Royal Manchester College of Music, where he met contemporaries including Peter Maxwell Davies, Alexander Goehr, John Ogdon and Elgar Howarth.
After selling his clarinets in 1960, he took a scholarship at Princeton University in the US, where he focused on composition and wrote the opera Punch And Judy. This work, along with Verses For Ensembles and The Triumph Of Time, established Sir Harrison as a leading light in British music.
By 1975 he was musical director of the Royal National Theatre in London, where he stayed until 1983.
In 1988 he was knighted and he was made Companion of Honour in 2001.
Sir Harrison's wife Sheila Duff died in 2012 and he is survived by his three sons and six grandchildren.