Primavera Kept the Magic of the Secret Show Alive

Don't mean to shout lads, but if you like both music and cans it's a received wisdom that Primavera Sound is one of the best weekends you can chuck your money at. Every May or June, Barcelona's Parc del Fórum opens up its warm arms to the crowds who descend for a weekend of watching people shred, sing or rap, before taking a dip in the sea. A diverse lineup spread across eight stages means that your musical tastebuds remain tantalised – this year I am pleased to inform you that I was able to watch both Skepta and Slayer within a day of each other – and because there's no camping, it's an altogether more pleasant experience than most UK festivals (give or take the 4AM Metro journeys back to your Airbnb).

The lack of camping means Primavera relies more on technology than other festivals – punters don't have to ration out their phone battery, hollering if anyone "has some charge" in the middle of a field, so you can jump on social media and the festival's app (sorry to get corporate) at your leisure. Organisers used both to tease secret sets by Arcade Fire, Mogwai and the especially elusive Haim over the course of the weekend, and, for my money, this was probably one of the coolest bits of the entire festival.

Regrettably, but also inevitably, I spent the first proper day of Primavera being a drunk British idiot (Don Simon sangria in a juice carton isn't your friend, just FYI), so Arcade Fire's secret set happened before I even knew about it. It was announced a few hours before stage time and was put on a much smaller stage than the band's official, mammoth 90-minute slot on the Saturday night. This way, Primavera both gave fans a chance to see a group who basically now only play arenas in a relatively intimate setting, and freed up their time on Saturday to see someone else – so far, so good.

On Friday morning, an ominous question mark emerged on the same page of the app where the Arcade Fire announcement had been. After I checked back a few times, the next secret band – Mogwai (above), who played an entire new album at their set – was revealed. If #rare musical experiences for the indie lads and ladies were what Primavera was seeking to provide, they were two for two.

The last surprise set of the weekend, however, was my favourite. As a white woman with a balayage who owns a number of cacti, it's kind of obvious that I'd be gassed to see Haim (though for what it's worth, I do actually think they're three of the best pop songwriters and performers out there – lead vocalist Danielle in particular is a menace with an axe), but it was even more of a treat to see them as a surprise. Earlier in the day, the festival uploaded a short, cryptic animation featuring text that read "We've Got Something to Tell You." Haim fans, who knew that the band's upcoming album is titled Something to Tell You, clocked the clue pretty quickly, and almost immediately the Primavera Twitter account's mentions were more clogged up than my arteries due to the amount of Spanish crisps I have eaten in the last week.

News eventually filtered down that Haim would be playing at 3AM, and sure enough, as my friends and I bowled up to the ordained stage at the ordained time, there they were, bashing out their album one track "Don't Save Me," their hair blowing in the early morning Barcelona breeze and Este's famed bass face working overtime. Haim's set was one of my favourites of the weekend firstly because yes, I like Haim anyway and had never seen them live before, but secondly the element of surprise cast its own spell. As an adult, it's hard to feel genuine novelty, but as I danced about to "Forever," I was genuinely excited to be there, and I think that that is the feeling that music festivals should seek to provide for those who attend them.

Where Primavera gets the concept of surprise sets right is in their willingness to book genuinely popular and in-demand acts to play them – it can feel like other festivals are less likely to do so (sure, Glastonbury having The Libertines show up is cool, but they're not necessarily what you'd call a "current" band). For many fests, Haim – whose profile is especially high while they're very aggressively on the album promo cycle – would be an extremely good, face-saving get after the last-minute departure of Frank Ocean. But rather than announcing their appearance, Primavera kept it quiet so that it'd feel extra special (a clever tactic to charm an audience denied Frank).

The same goes for Mogwai. Undoubtedly, the news that the Scottish band were to debut an album's worth of new material would have attracted ticket sales, as would the idea of seeing the astronomically massive Arcade Fire in a smaller space than most ever will. But, keen to maintain the fun sense of conspiracy that only a secret set can elicit at a festival, organisers kept the possibility of these experiences under wraps until the last minute, providing the sort of "you had to be there" moments that, really, are the bread and butter of live music.

Primavera Sound is a great festival for a lot of reasons – clean toilets, good food, no fucking mud – but surely its commitment to the great festival tradition of the secret set is one of its best attributes. Going to see live music is an extremely joyful thing, and there's little better than getting to see an act you love, even moreso if you're not expecting it. And if it's sun, sea and surprises you're after, you can't really do much better.

Lauren's dreaming about cans in the sun (and a Labour win) on Twitter.