Recently, I went to Primavera Club in Barcelona at Apolo, which is where some of the off-site gigs usually take place during Primavera Sound (set for 31 May–4 June 2017). Now, I know what you're thinking, because I thought the same – what exactly is Primavera Club?

According to Abel Suárez, one of Primavera Sound's bookers, it started as a small winter festival close to the philosophy of the main event. In recent years, however, it's been scaled down to be a showcase for up-and-coming bands that the organisers think are going to be big in the coming year. Some of the bands go on to play Primavera Sound the following year, says Abel, especially the local acts, which makes this a pretty unique chance of previewing the main event, not to mention seeing 30-or-so 'next big thing' bands in one place.

On the first night, I can see why the organisers might put Public Access TV in that category. The quartet from New York City remind me a bit of The Strokes at first, but as the set unfolds they seem less genre-focussed. It's a tad too rock 'n' roll revivalist for my liking, and dare I say a touch too accomplished to excited, but it certainly goes down well with the local Friday night crowd.

New Zealand's Yumi Zouma are more up my alley with their oozing synthlines, ethereal vocals and steady percussion. It risks being cloying at times, but when the four-piece veer more towards electro-pop, as in floor-filling finale ‘Alena’, it's an absolute delight.

Unfortunately I end up missing most of the local bands, but one of the few I catch is also one of the most memorable – Tversky. Walking in to a man playing saxophone along to some sexy electronica is a good start; the simple, repetitive percussion and basslines in the beginning belie the lavish synth melodies that are soon worming all over the songs. The sax player is constantly switching between his main instrument and the synths, while at one point he whips out a flute. It's virtuosity in the best possible way (a week later, at the 15th anniversary of pioneering Barcelona-based Foehn Records, I realise that the sax-player in question, Alan Himar, is in at least two other excellent bands, the devil).

“We have some strict rules when choosing the bands: [firstly] we try to bring only bands that haven't played in Barcelona so far,” says Abel, which partly explains the packed crowds and fizz of expectation in the air throughout the weekend. But while another of their admirable rules is that bands “should have only singles or a debut album, not more than one album,” this doesn't mean that all the acts are total musical newcomers.

Throughout the set of Canada's Operators, I'm thinking, “Where have these guys been all my life?” Only later on do I recognise frontman Dan Boeckner of Wolf Parade and Handsome Furs fame. Boeckner and synth player Devojka spend the set writhing over synths and thundering basslines – exhilarating stuff.

On the second day, the fast-paced parts of Minor Victories' set seem like a heavier post-rock Pains of Being Pure At Heart, though the thought does cross my mind that a supergroup doesn't quite fit with Primavera Club's ethos – the band is made up of members from Slowdive, Mogwai and Editors. While I'm not a fan of two of the above, however, Minor Victories prove to be more than the sum of their parts; Rachel Goswell's delicate vocals somehow managing to rise above the thunderstorm of guitars is a thing of wonder and beauty.

Perhaps what impresses me most over the weekend is how much enthusiasm the local crowd have towards a bunch of relatively unknown bands who've never played in Barcelona before. Seeing so many up-and-coming bands can pall after a while, and to be honest, I grow weary at some point late-ish on the second night. I'm rather taken at first with C Duncan from Ireland, whose immaculately crafted dream-pop songs are doused with classical influences; it sounds like a piano-heavy Grizzly Bear. But just as when seeing the latter live, I feel a bit woozy after a while. Sadly, I arrive too late on in the set of Holland's PAUW for their raucous psych-rock to fully revive me.

It takes me much of River Tiber to get over this malaise. The keyboard-electronica jams sound rather James Blake-y, while also tapping into the pop-soul trend, which is all very well but not quite what I need right now. Yet by the stripped-down closer 'Let You Go', performed alone by main man Tommy Paxton-Beesley with nothing but an electric guitar, I make a full recovery, and find myself tweeting the following: Ok ok ok that last song by @rivertiber just saved my faith in everything, you moved me man ok bye

It's easy to see why all of the above have been selected by the organisers – each one is accomplished, confident, and easy to imagine gracing the stages of Primavera Sound next year. At times I find myself longing for a little spontaneity, a spark of punk-rock abandon – a mistake, even. But then Seth Bogart for one offers something of that sort; a scantily clad extrovert bouncing about the stage to piped music, his OTT slutty pop songs have the crowd in raptures. Another artist worthy of honourable mention is Londoner Kelly Lee Owens, who can hardly be accused of slotting easily into the zeitgeist with her tremulous space jams and strange haunting vocals.

And so, even though I keep telling myself I'll give Primavera Sound – the world's biggest car-park-festival-by-the-sea – a miss this time, I know where I'll probably be when the day cometh. While Primavera Club may play it a bit safe at times, I can think of few other ways to see so many promising, up-and-coming bands in one place, and an audience so up for that sort of thing. Which, for all its faults, is what I love most about Primavera Sound itself.

Photo Credit: Dani Canto

Primavera Sound takes place in Barcelona from the 31 May to 4 June 2017. For tickets and information, visit the festival’s official website.