Bonnaroo has a reputation for being an all-night bender. But even if you suspect that the happy atmosphere here may have something to do with a large stock of illicit substances, you can't doubt the genuine goodwill that sloshes around the place. When Mumford & Sons had to pull out of the headlining slot because of bassist Ted Dwane's sudden illness, Jack Johnson – only at the festival to hang out with his friends Animal Liberation Orchestra and listen to music – was asked to fill in, despite the fact he hadn't performed with his band in more than a year.
And so Manchester, Tennessee hosted a Jack Johnson comeback gig, and no one minded when he forgot a few lyrics. He even whipped up a song about the saga, with a chorus specially crafted to allow the crowd to howl out "Bonnaroo", before leading them in a singalong of Mumford's The Cave. There was Brushfire Fairytales, an acoustic encore, and some lively backup from the Preservation Hall Jazz Band.
This being America's version of Glastonbury, however, there were plenty of options to suit the eclectic ear. You could get up with Nas, get down with the National, or get high with Empire of the Sun; you could soak in a whole magical day of acoustic picking courtesy of Ed Helms's Bluegrass Situation. There was no doubt about who Bonnaroo's big star was this weekend, however. Rumour has it the organisers have been trying to secure Paul McCartney for years, and he arrived on Friday night with a phalanx of police outriders, taking to the stage to shouts of: "We love you Sir Paul!"
He more than earned his starry passage with nearly three hours of greatest hits, causing chaos in the schedules. ("Paul McCartney wanted to rock," said an apologetic Oliver Sim as the XX kicked off their moody set half an hour late. "What can you do?") Some punchy Wings numbers and an attitudinal Paperback Writer set the tone; McCartney doesn't need to work a crowd, but his well-honed set kept them busy, from a flamenco-flavoured And I Love Her to a frankly dotty Altogether Now, accompanied by graphics of blinking, blobby characters that suggest Macca's next project may be a kids' TV series. There was the civil-rights-inspired Blackbird, and later he held his fist in the air and declared "Free Pussy Riot!" before launching into a kick-ass rendition of Back in the USSR.
Between songs, he told the occasional story about Eric Clapton or Jimi Hendrix, and dedicated songs to Linda and Nancy. If an occasional number misfired – an underpowered Eleanor Rigby, an exposed solo on Here Today – that was never what you were going to remember; instead, it was the moment when, halfway through the intro to Live and Let Die, a giant image of a building resembling Buckingham Palace was blown up to a surprise volley of on-stage pyrotechnics.
It says something about the breadth of the festival that the next day, at a smaller stage, you could watch a musician doing a punk parody of Blackbird and shouting "Mac sucks!" to the delight of his audience (this was Mac deMarco, the slacker-rocker from Alberta, who had plenty of buzz at the festival for his goofy iconoclasm). Or, for example, on one afternoon see Wilco deliver an amiable set of alt-rock – Nels Cline's extended jams thrilling the guitar purists – and the next watch Björk emerge, her head subsumed in a cloud of shimmering fibres, her body wrapped in contoured silver.
A 14-strong choir in metallic robes accompanied the Icelander's ethereally voiced songs, underpinned by xylophone clock-beats. Her song Crystalline was mesmeric, Björk's pitter-patter around the stage accompanied with Wonder Woman punches; Pagan Poetry was a cosmic aria. The choir danced loose-limbed around the stage like Zooey Deschanel on mescaline.
It seems a strange decision that someone whose act is so visually compelling chooses not to share it with the masses via the video screens. As the sun went down, she turned the set into an EDM party, leaving the more ambivalent audience members to stand bemused as she exhorted them to "Declare independence!" In the next field, the Lumineers, whose shout-along folk rock has found such an adoring and high-pitched fanbase, caused virtual gridlock.
Still, they couldn't compete with R Kelly, whose showmanship reached new literal heights when he began his performance on a crane high above the Which Stage. Slick, sure-footed and displaying a wicked sense of humour ("They told me backstage, no cursing. I just laughed at those motherfuckers"), he maintained a relentless momentum through his opening 40 minutes – before breaking into an improvised ballad. "Can I get a towel to wipe my face," he crooned, then returned to his analysis of how many sexy ladies there are, with the melancholy of a man who knows he can't have them all. You didn't even need to be at the stage to get a taste of his grand finale, I Believe I Can Fly, for which festivalgoers were treated to a gigantic flock of paper birds winging their way through the night sky.
Minutes later, Kelly was covering Sam Cooke (A Change Is Gonna Come) with Jim James and John Oates at the late-night Superjam. Bonnaroo's no-curfew policy means the party goes on all night in these legendary sessions, and this year saw Wu-Tang Clan mash it up with Solange, John Oates and Jim James cover 1999 and Billy Idol yelling at the crowd to Bang a Gong (Get it On). Wandering around at 3am in T-shirts and shorts, you realise why rural Tennessee's an ideal venue. On the final night, as Tom Petty and the Heartbreakers closed the festival at the main stage, the heavens opened – and his audience rocked out to him, delighted, in the rain.
