Forty per cent of London is green space. And what we do with all that grass – all that potential – is pave it with music festivals. This year, Hyde Park hosted Billy Joel and Bruce Springsteen. Gunnersbury Park had Boygenius. Finsbury Park welcomed Pulp and Travis Scott. Field Day is a staple of the season. Always falling on a Saturday in late August, the day is wholly reserved for electronic music.

Reams of twentysomethings make the pilgrimage: set off from wherever, change at Bank, District Line to Mile End, 15-minute walk, enter, set aside £7.50 for a can of warm Red Stripe. Everything is very clean: the organisers don’t want Woodstock. The first thing you see upon entry is a stand to buy Alpine’s MusicSafe Pro High Fidelity Earplugs. Of all the carefully curated food stalls, the queues outside Vegan Fried Chicken were the longest. Gone are nights in sticky tents in Donington and Thin Lizzy-induced tinnitus. Welcome wellbeing zones, organic gyros stalls and central London noise curfews. There’s a Field Day uniform: white vests and pearly necklaces for men; low-slung cargo pants and Doc Martens for women. Girls dress like boys, and boys dress like girls.

Aphex Twin – the headliner – is really called Richard D. James. He’s a DJ and electronic producer, has been making music for almost 40 years and I love him. So do Daft Punk, Steve Reich and Thom Yorke. He’s why I’m here. His first album, Selected Ambient Works 85-92, is the only work of music that’s ever convinced me that synaesthesia might not be baloney. His songs conjure up specific images in my head, always the same: ‘Tha’ is a municipal swimming pool, ‘#3’ a pair of eagles circling over an empty dessert, and ‘QKThr’ a lonesome hotel concierge shuffling bags.

It’s the music of the ‘non-place’, the soundtrack for impersonality. His music exists in an uncanny valley; not quite elevator music, not quite royalty-free – slightly too weird for that – but dancing on the edge. Songs such as ‘aisatsana [102]’ and ‘Alberto Balsalm’ are the soundtrack for a popular genre of TikTok – videos that mesh together unrelated clips of tranquil loneliness: a dark road at night, a hotel corridor. People love them and repost them and find them relatable. His songs have become the soundscape for an ennui that people want to share.

It’s a cliché to say Aphex Twin is an enigma. But yes, Aphex Twin is an enigma. He doesn’t own a phone, he drives a 1950s armoured car fitted with a machine gun, and he lets out little emotion. In the early 2000s, Richard was asked if he would tour with Radiohead after the band said he was their biggest influence for Kid A. ‘I wouldn’t play with them since I don’t like them’, he replied. This gig was his comeback performance after a four-year break. A quite staggering number of people flocked to the East Stage: there was little room to dance.

Not that anyone could if they wanted to. Not a hint of a hit all night long. He ditched the muzak. It was an attack, not a gig: stop-start blares, schizophrenic synths, artillery-fire drums with not a hint of structure, all set to contracting and expanding wild bright lights. I should have got the Alpine MusicSafe Pro High Fidelity Earplugs. A 50-quid, hour-and-a-bit troll. The audience, some of the Russell Group’s finest, ached to get it. ‘Like, it’s amazing,’ a guy behind me lied. ‘He’s pushing the boundary of what is sound and what is music!’ I think I saw him in the queue for vegan chicken earlier.

Ten minutes before the end, me and my friend cracked. ‘Shall we go?’ We scuttled away on the District line, and I imagined Aphex Twin coming offstage, laughing.