Green Man review: Idles deliver an optimistic, exhilarating end to a festival that’s really hit its stride

With relentless rain most of Friday, you could be forgiven for choosing to hang out in the large tented stage all day – but if you came for the dryness, you’d stay for the spirit-lifting line-up

Joe Talbot of English punk rock band Idles (EPA)

Now in its 17th year, Green Man festival sold out again in record time. But it’s easy to see why revellers loyally return year after year – and it’s not just for the music. Set in one of the most beautiful festival sites in the UK, on the Glanusk estate in south Wales, its outdoor stages are framed by the Black Mountains. Even when shrouded in heavy rainclouds – as on this year’s very soggy Friday – it makes for a stunning backdrop for a friendly festival that still feels much smaller than it’s 20,000 capacity. By day, kids run free and wild, entertained by family-friendly workshops and laid back crowds at the main stage; by night, grown ups who’ve been sampling the impressive array of local cider and craft beers – there’s no screeching branding here – can run wild too, with DJs until 4am.

With relentless rain most of Friday, you could be forgiven for choosing to hang out in the large tented stage all day – but if you came for the dryness, you’d stay for the spirit-lifting line-up. Marika Hackman’s New Wavey new songs flow by with chiming guitar and liquid vocals, although the acoustics made it a little difficult to make out some of her lyrics – even though, as she makes a point of telling us, they’re about sex and masturbation.

Welsh artist Gwenno’s set of swirling, psychedelic synth-pop also sounds a little murky, but builds to a rousing, inclusive finale, following a plea for open-mindedness and generosity to other cultures: Gwenno sings not only in Welsh but also Cornish, and speaks movingly about how it gives her hope to see audiences singing along to “a language only 500 people speak fluently”. If that sounds all a bit serious, it’s worth pointing out that the song we were encouraged to join in on is about eating cheese. Amadou and Mariam bring sunshine wherever they go, and after 40 years of playing together, the Malian husband and wife duo are still on very fine form. Their warm jams and grooves plasters smiles across the faces of everyone who’d squeezed into the busy tent to watch.

Two of Saturday’s highlights arrive mid-afternoon, over on the main stage. Stella Donnelly gently lilting songwriting, stiffened by her astute lyrics, proves captivating. A thoroughly winning, funny performer, she has the crowd in the palm of her hand. But given she found fame by the eerie timing of the release of her song about sexual assault, “Boys Will Be Boys”, just as #MeToo broke, Donnelly also continues to use her gigs as a platform to speak out. It’s a generous rather than hectoring offering: Donnelly dedicates the song to her brother and the many other “gentle men” in her life, condemning the “boys will be boys” tag for suggesting that abusive behaviour is somehow inevitable.

Blasting off in a very different direction are Sons of Kemet: two furious-paced drummers, a saxophonist and a tuba player scorch the stage with their high-energy, technically mind-bending blend of Afrobeat and jazz. It’s a busy day for the saxophonist Shabaka Hutchings, who also rounds off the night in the Far Out tent with his even more raucous, improvisatory set with his other band, The Comet is Coming, closing after a headline live set from Four Tet on the main stage that brings together the moody and the ecstatic in a barrage of beats.

A sunny Sunday afternoon at the main stage is treated to the sweetness of Anais Mitchell, doing a stripped-back set with just one other guitarist. She plays songs from her wonderful folk opera album Hadestown – now a Tony-scooping Broadway musical – and other favourites from her back catalogue. She’s followed by Aldous Harding, who becomes an ever-more captivating, and deeply strange, performer. Her striking, sonorously rounded voice has a haunted quality, but it’s the wild array of exaggerated facial expressions that really unnerve: she rolls her eyes back in her head, gurns, and then grimaces a wicked smile.

Despite not headlining, Eels draw the biggest audience of the week. They are an absolute treat, reeling off crowd-pleasing numbers – from “I Like Birds” to “Mr E’s Beautiful Blues” to a gleeful cover of “Raspberry Beret”. Following them, Sharon van Etten offers a more sombre mood. Hers is a masterfully assured, poised performance, as she plays songs from her excellent recent album Remind Me Tomorrow that showcase all of its muscular power.

The festival ends each year with the ritualistic burning of the green man – a giant wood and straw construction. But just before the flames are lit, the Far Out tent is burnt up in a blaze of light and heat of its own, courtesy of Idles. The crowd goes ecstatic for their sweary, shouty, messy old-fashioned punk rock, complete with stage diving and stage invasions. But big-hearted speeches about the NHS, mental health and how much they’d like to thank the people who clean up the festival site prove that masculine rock doesn’t have to be all swaggering arrogance. They deliver an exhilarating, optimistic end to a festival that’s really hit its stride.