He was a landscape painter of a composer – a great friend of ''Tas'' Drysdale, who took him under his wing and provided early encouragement. Peter was a good enough draftsman for his family to have imagined him becoming an artist, and his painterly eye served him well as a composer.He once made a 360 degree line drawing of the hills around Canberra, and superimposed the line over manuscript paper to create the haunting opening melody of Irkanda 1. He had an ear for this Great Sandy Island, and a gift for capturing its contours and colours; the dusty reds, earthy oranges, pale yellows and browns. It could be so evocative, the sense of parched grass almost made you itch. His music transported the mind to lands he had often not visited, yet remarkably his desert music sounds like the desert, his Kakadu like Kakadu, and his Torres Strait works have that pale turquoise glow of the Arafura Sea.

Peter was a great marcher to his own drum. His personal magnetism drew us into step behind him, and before long ''Australian music'' had swelled into a happy, diverse and vibrant throng. He was a sun in our sky; a ship in whose slipstream we could follow; a champion who blazed trails where few had gone before. It will be very difficult for all of us to learn to be our own ''superhero'' without him.

We love his music because he loved it so deeply, and strove so hard to make it true. It all unfolded so well, everything in its proper place, all the proportions so harmoniously balanced. If architecture is frozen music, Peter thought music was ''emotional architecture through time''. Hearing his music was like watching an enormous flower bloom. You knew what was coming and yet every time, you just had to sigh at the climax, as the petals opened in an orgasm of love underpinned by a beautiful sadness.

This contradiction, between the optimist and the deeply felt man who grew up in idyllic green, post-genocide Tasmania, was a balanced tension that saved his music from sentimentality. So much of his happiest music sat side-by-side with a parallel sense of disquiet. Pain was ever present in his expression of love. His sad owl eyes always seemed to be on the verge of tears, and yet he remained composed, observant, stoic and fully resolved to the task. He worked a backbreaking, double career as a university professor and full-time composer for 35 years, running one deadline into another with few breaks. He was a hard-working, hard-partying ox of a man, and when he retired from Sydney University and could finally rest, he tumbled into the most profound depression as he finally paid the piper for all that overtime. It was a shock to realise that this force of nature was indeed human.

What saved him, as much as the medications, was this sound which would fire his imagination, first heard when William Barton played didgeridoo in Sculthorpe’s orchestral work Earth Cry. In August 2002, a historic Australian musical earthquake occurred in Brisbane. A young man whose undeniable presence shone out of him calmly took the stage and, with his didgeridoo and singing, added a subterranean layer of counterpoint to one of Sculthorpe’s finest scores, as deftly as a hand sliding into a glove.

It added an animal physicality to Peter’s music. Einojuhani Rautavaara, Sculthorpe’s equivalent in Finland, whose music was also on the program, said the recording sounded ''as if there was a beast let loose in the orchestra''. I think it scared him. Yet that deep river of energy seem to lift Sculthorpe back up like a wave, making him and his music powerfully relevant in a pre-apology Australia, thirsting for reconciliation. Functioning almost like a record stylus, his music stood at the precise point of engagement with an issue that gripped the nation’s soul. It resolved the contradiction of Sculthorpe’s early life in Tasmania; Anglo and white, yet searching for remnants of its lost Aboriginal culture. Touching those deep resonances enlivened and illuminated his potent late works, reaching its zenith in the Requiem, his powerfully austere masterwork.

When I recently looked up the complete list of Sculthorpe’s pieces over the 16 years I worked with him, the number of works staggered me. If included here, it would come to more than two pages of titles, many of them among his greatest works, as well as numerous reworkings, refinements and recastings. The scale of his productivity is simply monumental. He had chosen not to marry; instead to focus on his compositional children, and the fertility, the scale of the family he produced, is mind-boggling. If you play an instrument, it is almost certain he has written something beautiful for it.

We did many of these late works in the Canberra International Music Festival. He was our Composer Laureate, and in 2009 we remounted, after a year of revisions, his greatest work, Rites of Passage, originally written for the opening of the Sydney Opera House in 1973. We created the largest retrospective to date for his 80th birthday, commissioned the chamber version of his Requiem, the Kyrie for cello and strings, the guitar concerto Oh, T.I., and a radiant work, fittingly titled The Shining Island, an expansive outpouring of sunlit melodies, written in memory of Henryk Gorecki. It was no accident that Canberra became the centre for so much of his late music. He felt that in the future people would come to find him here, in the boxes of the National Library, nestled amongst his scores, writings and his beautiful things.

In 1998 I promised his publishers, Faber Music, that I would act as his editor and oversee the completion of his catalogue. After 15 years of substantial revisions, we found ourselves in a race against time as Peter suffered though a year of cruel, agonising work while recasting the final piece, his television opera Quiros, about the explorer who named Australia. Newly titled as The Great South Land, the music only arrived a few days before the nationally broadcast premiere, but without Sculthorpe, who was by now too unwell to attend; and soon after, in Charles Ives’ words, he was no longer able to keep his sailboats ''up and sailing''.

It takes a great concentration of the mind to compose, and the secret to Sculthorpe’s consistency was his ability to sit there, for weeks on end, like an Easter Island statue, at his piano and desk, setting the notes like a jeweller on the five lines of his staves. A beautiful mosaic, inching ahead at a few seconds of music an hour, towards the light at the end of the tunnel, where ultimately it enriched us all.

Sculthorpe was deeply inspired by D.H. Lawrence and in particular his poem Sun in Me.

A sun will rise in me,

I shall slowly resurrect.

already the whiteness of false dawn is on my inner ocean

A sun in me.

And a sun in heaven.

And beyond that, the immense sun behind the sun,

the sun of immense distances, that fold themselves together

within the genitals of living space.

And further, the sun within the atom

which is god in the atom.

Whichever sun Peter is orbiting, I wish him safe voyage and all of our love.