Artist, mystic and political radical William Blake is today considered one of the major cultural figures of the Romantic Age. And, although he was virtually unknown as a poet during his lifetime, Auguries of Innocence has become one of his best-loved works. Rich with symbolist imagery and social criticism, the poem meditates on the interconnectedness of all living things, the inherent goodness in nature and the fragility of human innocence. Its message has proved so popular that references to the poem dot the modern-day cultural map, from The Doors to Agatha Christie to the video game Devil May Cry. It even became the punchline in a recent social-media trend in which users paraphrase the text as a response to different modern-day banalities. (‘Do you know how to parallel park?’ ‘No, but I know ... how to see the world in a grain of sand and a heaven in a wild flower. I know how to hold infinity in the palm of my hand, and eternity in an hour.’)

Eric Whitacre first came across Auguries of Innocence as a teenager. He was immediately struck by the parallels between its first four lines and another of his teenage discoveries, Zen Buddhist philosophy. ‘It’s about taking a single moment, or something as insignificant as a grain of sand, and seeing within it an entire universe,’ he explains. ‘The world is complete in that moment if you simply focus on it. It’s about becoming a beginner again or, as a Zen Buddhist would say, having a beginners’ mind – letting go of the sickness of experience and seeing the world as it is.’ He held the lines in the back of his mind from that moment onwards, hoping that one day they might provide the foundation for a piece of music.

When, last year, a commission came through for a work celebrating the 100th anniversary of the BBC Singers, Whitacre began by musing on what the past century has looked like, comparing it to where we are now collectively. This led him straight back to Auguries of Innocence. Not unlike those social-media users, he saw in Blake’s poem a foil to the noise and chaos of the modern-day world: ‘Moments seem to be chopped up into oblivion; all of reality is TikTok-like. My idea, then, was to make an hour’s worth of music setting just those four opening lines – to do exactly what Blake compels us to do and find “Eternity in an hour”.’

The resulting piece comprises eight uninterrupted movements. Each represents a ‘grain’ of poetry, which is set cumulatively so that, by the finale, all four lines are heard in full. The work is scored for choir, string quartet, piano and synthesizers, and is conducted tonight by Whitacre who, along with electronic artist Lesjamusic (aka Nick Lisher), will be capturing acoustic elements and manipulating them in real time. (Whitacre imagines himself as an 18th-century conductor, leading from the ensemble, transplanted to the 21st century.) This process is also reverse engineered, with the choir and strings instructed at certain points to listen out for the electronics and to respond in kind.

Whitacre likens this back-and-forth to ‘smearing sonic paint’. Heard atop drones in a series of drawn-out, meditative gestures, the cumulative effect is reminiscent of both Minimalism and ambient music. Indeed, Whitacre cites the influence of Minimalist composer Steve Reich and ambient-music pioneer Brian Eno, particularly in the way both set up patterns that induce a sense of expectation, then deliberately subvert them: ‘It’s not going to develop the way you think it is,’ says Whitacre of Reich’s music. ‘And, when you surrender that sense of expectation, you find yourself in the moment, floating on those waves of sound.’ This resonates with the ideas at the core of Eternity in an Hour: taking a single moment and expanding it for minutes at a time; ‘finding the exquisite beauty in a single, simple musical gesture’.

All this represents something of an artistic pivot for Whitacre, who made his name with short a cappella works, and who has never before incorporated synthesizers into his ‘classical’ compositions. (Though he did start out as a ‘synth guy’, while still a high school student, before he could read music: ‘I thought I was going to be in Depeche Mode!’). The synthesizers in Eternity in an Hour are also significant on a symbolic level:

As I really started to think deeply about the instrumentation, I realised how perfectly [electronics] fitted with the first line of Blake’s poem: the word ‘grain’ is now part of the vernacular of synthesis. ‘Granular synthesis’ is where you take a sound sample and chop it up into millions of pieces, or ‘grains’. These are then used to make sprays or clouds of sound. And so, by doing this during the performance, I’m integrating Blake’s words on an even deeper, poetic level.

One quirk of this approach is that, by giving synthesizers such a prominent role, no single performance will ever be the same: electronics rarely do exactly what you expect them to. This represents another, very deliberate pivot for Whitacre who, up until now, has aimed for absolute control over his output, composing what he calls ‘hyper- meticulous’ music. ‘I often write small and compact, so that every cog of the machinery is tuned to how I want it,’ he explains. ‘But with this piece I’m actively trying to let go of that ... On a very personal level, it’s a path to letting go, to being present – to finding a universe in a grain of sand.’

Still, a line can easily be traced between Eternity in an Hour and Whitacre’s earlier output. As with the works that made his name, such as Cloudburst (1995), Sleep and Lux aurumque (both 2000), on the surface the piece is very approachable. Yet it is also layered with highly personal ‘meaning upon meaning upon meaning’. Whitacre cites his 2018 work The Sacred Veil, recorded most recently with VOCES8 and tonight’s pianist Christopher Glynn, as the culmination of years practising this symbolism. ‘There is endless referencing back-and-forth, with the text, numbers of measures and movements all interwoven,’ he explains. It is no accident that there are eight movements in Eternity in an Hour: eight is two cubed, and two is a number used frequently in electronics. ‘Now I’ve fully embraced this, trying to go deeper with each new piece. My mind keeps saying: every single gesture has to be connected to the larger philosophy and structure. It’s my way of trying to make sense of life in general.’ (The irony here is not lost on Whitacre: ‘A real Buddhist monk would come and hit me on the head with a bamboo pole and say “Stop it! Sit, breathe!”’)

Whitacre has worked with the BBC Singers on several occasions. He came to the UK in 2017 to perform Arvo Pärt’s Passio with the group, alongside some of his own works, and has directed the Singers in two Proms performances, in 2012 and 2015. Knowing these musicians personally is key for the composer. It allows him to reflect specific musical personalities in the score: ‘Whenever I write a bass note I imagine Jimmy [Holliday] singing it, and how he would respond to it. It’s the only way I know how to write.’ The music has also been tailored to the performing space (‘so magnificent and then so weirdly intimate at the same time’) and to the Proms audience itself, which, Whitacre says, has an ‘energy and openness that I don’t find anywhere else. People have turned up to be transformed.’ This goes some way to explaining the ambition and novelty that Eternity in an Hour represents: here is an opportunity to push boundaries.

Whitacre is keenly aware of the imposing lineage of which he now forms a part. After all, the BBC Singers has premiered works by many of the great 20th- and 21st-century composers, from Stravinsky to Poulenc to Judith Weir. In his own words:

In the context of this being the group’s 100th anniversary, and with everything that it has gone through in the past two years, there are no words for me to describe how humbled and honoured I am to be working with the BBC Singers, and how unbelievably important this institution is. It’s profoundly humbling to be just the smallest part of its story.