The stetsons start at the tube station, crowning the heads of perhaps half the punters making their way to the opening night of Country to Country 2018. Launched in 2013, the festival has evolved even as country music itself has sprung off down a dozen different byways; starting as a two-night, one-city shindig, C2C now sprawls across three nights and, with the addition of Glasgow and Dublin, three cities. The chrome-plated O2 isn’t a natural home for music rooted in what Sugarland singer Jennifer Nettles calls “brokenness and realness”, but needs must – there are so many stages that it wouldn’t fit anywhere else. Underlining country’s growing stature in the UK, Radio 2 sets aside three primetime hours on Saturday night for a live broadcast.

The hats, and the anchoring commitment to realness, are the only constants of an event that heavily favours the new and the now, leaving traditionalism in the hands of a scant few acts, such as Friday headliners Tim McGraw and Faith Hill, and Sunday’s second on the bill, Emmylou Harris. (To be fair, the reception that greets both country’s glamorous first couple and the resplendent Harris hints that tradition is still very much alive.) The millennial artists who are reshaping the genre are here in their numbers, further blurring the lines between country and pop, rock and even rap. A dazzling Lukas Nelson, who has inherited his father Willie’s high-and-lonesome vocal style, pinpoints the way priorities have shifted when he comments: “We play rock’n’roll, but with a little twang.” And sometimes the twang is notably secondary, as with Alabaman Walker Hayes’s set; he thuds and booms with the help of a loop pedal, jabbing an accusing finger at life.

Meanwhile, Grammy-winning Sunday headliners Little Big Town look like Abba and open with a none-less-country version of Elton John’s Rocket Man. They later revert to type with warm, rootsy harmonising, but the message is that “country” now means whatever you want it to mean. Even McGraw and Hill arrive holding hands to a Bat Out of Hellish rock overture, followed by the Aretha Franklin/George Michael pop grinder I Knew You Were Waiting for Me. Drawing the biggest crowd of the weekend, the duo play their individual hits but are more powerful when duetting: a soft argument in favour of marriage?
While Nashville has never been short of female musicians who can pulverise errant men with one well-turned aphorism, many more have lately been emerging. C2C’s gender-equal billing spotlights so many purposeful, unencumbered women that it’s easy to believe the glass ceiling has taken some sledgehammer blows lately. One of Friday’s key acts, Kelsea Ballerini, honed her style by listening to Taylor Swift; like Swift, she effectively mixes bounciness and pithy side-eye (“I thought I’d miss you, but I miss me more/Miss my own sheets in the bed I made up”). On Sunday, Margo Price follows the sartorial traditions – cowgirl hat, white satin suit – but kicks her set into orbit by getting behind the drumkit and busting out a fabulous swampy groove.
Kacey Musgraves, who closes Saturday, is a cheery but self-contained contrast to the weekend’s boisterous spirits. Announcing that she has recently married, she unfurls “trippy” material from her forthcoming album, Golden Hour. It’s a newlywed’s dreamy riposte to the ugliness of current politics, but the arch cynicism of older tracks like Stupid somehow feels more in keeping with the times.