This was a surprise. One of the most iconoclastic British composers of his generation, whose music had made Mad Kings rave and rage, who had made music theatre for a nude Antichrist and parodied the sacred cows of British institutions, who had made popular culture part of his creative mélange of influences, and who had rejected romanticism and English pastoralism for hard-edged dissonance and modernist-medievalist objectivity: Peter Maxwell Davies wasn't supposed to be in the business of writing symphonies in the 1970s. And yet, when Simon Rattle conducted the world premiere of Davies's Symphony with the Philharmonia in London in 1978 (no-one could have known then that this was the start of a cycle of nine symphonies, with a 10th on the way next year), they heard a gigantically ambitious, nearly hour-long symphony that didn't attempt to deconstruct the form or the idea of "the symphony", but rather to reinvigorate it with an explosion of turbulent dynamism. This is music that seethes and churns and shimmers and glows, in which your ears are pitched violently out there on a tempestuous ocean of musical possibility.

But Max didn't think he was embarking on a symphonic odyssey when he started work on this piece. The music grew from a single movement, a piece that would have been called 'Black Pentecost' after a line in a poem by the Orcadian writer George Mackay Brown, Max's most important creative ally in his new home of Orkney. Max moved there in 1974 and immediately began work on the music that became the Symphony. (There is, incidentally, a piece that really is called Black Pentecost in Max's catalogue, composed for orchestra and two vocal soloists in 1979.) This original chunk of music eventually became part of the second movement of the completed symphony; as Max says, the music started "budding and putting out shoots, and although I had firmly drawn a final double bar-line, it was reaching out across this, suggesting transformations beyond the confines of a single movement."

And it's that idea of continual, quasi-organic growth and ceaseless musical development that defines the experience of listening to this Symphony. Max talks about the antecedents for some of the things you'll hear in the piece: the way the second movement gradually picks up speed and momentum is an idea Sibelius first used in his 5th Symphony, in which the opening movement melds into the scherzo; Sibelius's 5th is also the inspiration for the very end of the piece, and the pregnant spaces Max leaves between the symphony's final chords. What Max describes as the "cross-phrasing and time-perspective devices" in the long slow movement, which comes third, develops ideas from the start of Schumann's Second Symphony, and he says that there's a relationship between the way his final fourth movement works and Boulez's "Don" from Pli selon pli.

But it's what's new and individual about this symphony that's more striking than what might be borrowed. Most obviously, there's the way it sounds. Max's large orchestra glitters with a halo of tuned percussion – crotales, glockenspiel, tubular bells, marimba, important roles for the harp and celesta and even an unusually melodic part for the timpani. The luminous instrumentarium is an integral part of its soundworld rather than a decorative add-on, and it give this symphony a unique, sparkling iridescence. These instruments make a kind of sonic sea-spray on top of the larger waves of the music's energy or they're a symphonic metaphor for the infinitely subtle play of light on the surface of the water. As Max says, this is the first orchestral work of his to be "permeated by the presence of the sea and the landscape of this isolated place off the north coast of Scotland".

There's an especially magical moment of sea-sounds a few minutes into the finale: sea-gull calls in the woodwind, weightless trills and frills in the high-register sounds of the rest of the orchestra, as if Max had stopped his symphony to suspend us above the waves on an Orcadian cliff. But what makes the whole symphony so powerful, I find, is that it does not lose sight of its essentially elemental energy, however kaleidoscopic the sound world. Listen to the undercurrents that drive and drag the slow movement through its 15 minutes, the way the heightened lyricism in the upper strings is set on a sonic quicksand of shivers, tremolos, and sea-quakes underneath; there's the quicksilver, multi-layered wave-play of the first movement; and above all, the irresistible speed and foment of the symphony's final few minutes.

So: in 1978, a new kind of genuinely symphonic discourse set on an unpredictable modernist sea of non-tonal harmony and ever-changing architecture. Max's is a magnificent achievement for the symphony and for his own creative output.

Key recordings

There are two recordings of Max's First Symphony: his own, with the BBC Philharmonic Orchestra, which sounds more colourful and considered than Simon Rattle's 1978 recording with the Philharmonia. Rattle's is rawer, more expressive, and more exciting; they're complementary readings of this masterfully maritime symphony.