What do you picture when you think of Latvia? It may be that you picture nothing, but pay a visit to Positivus Festival and you will have images to last you a lifetime. Over the course of an hour’s drive from Riga, you travel through unmanicured forest, spruces and pines towering overhead, until an opening emerges. This festival has made its home in a dramatic forest clearing near the Estonian border since 2007, a pocket of secret merrymaking that feels a million miles away from civilisation. If that isn’t enough for you, it also happens to be positioned along the edge of an extended, sunlit Baltic Sea beach, its sand as fine as powder. Sold? Well, there’s music too.

When Margaret Glaspy takes the stage over at the festival’s second stage Nordea early in Friday’s proceedings, the crowd barely registers her presence at first, such is the range of distractions at hand. But her earthen, organic music is a siren and the rows of wooden planks that fill the area are soon bending under the weight of the crowd. At times, her guitar sounds like a buzzsaw revving up, readying to chop down the surrounding timber, her distinctive voice sculpting frustration into something reflective and mature. It is a set later praised by Maximo Park frontman Paul Smith, shortly before he loses his voice midway through the Sunderland band’s set. It does nothing to slow his boundless, zigzagging energy on stage, nor to dampen the crowd’s enthusiasm, but it does draw attention to how damn hard those songs are to sing.

More subdued are Cigarettes After Sex, the blossoming project of El Paso’s Greg Gonzalez. Their hushed, heart-worn songs remember the Cocteau Twins rule that guitars can lurch and jangle without popping, and when teamed with Gonzalez’s vocals and the low hum of the rhythm section, it hits the attentive section of the crowd like the world’s gentlest tidal wave. There are, it must be said, parts of the audience more interested in their own conversations – their loss.

The same problem does not afflict Pixies’ headline slot. Indeed, the opportunity for talking at any point once opener ‘Gouge Away’ kicks in is virtually nil, either in the crowd or on stage. Their set is better described as a medley, cramming thirty songs into less than ninety minutes. Black Francis is no orator, but the songs speak for him, and with all six albums represented there can be no complaint from any corner. Debut EP Come On Pilgrim, celebrating its thirtieth anniversary, is surprisingly prevalent; perhaps more surprising still, the predominantly Latvian crowd knows it by word. It is a treat to see one of alt-rock’s Mount Rushmore still firing on all cylinders.

Saturday starts for many with Californian wunderkind Kamasi Washington and band. Some early technical problems (Kamasi’s sax mic was dropping out) only lead to an even more indulgent series of keyboard and bass solos, and the reception from an impressive afternoon crowd is a sign that this will be a special set. Guitar bands, if you’re lucky, provide you with enough of an energy surge that you begin to approach lift off, but with great jazz, that’s just stage one. At several stages a band member leaves their colleagues with disbelieving smiles whilst they wonder off into their own self-created stratosphere, none more so than Joshua Crumbly on bass, to whom Kamasi liberally refers as a “genius”. The set’s popularity is proof of the open-mindedness of the Positivus audience, which hopefully has been registered by those responsible for the festival’s future booking.

Digging deeper into the festival’s offerings, the charming Palladium stage plays host to London-via-Sweden’s Francobollo. Their set ranges from skipping Gorkys-like quirky indie to a meatier, more muscular guitar-driven intensity. Recent single ‘Worried Times’ is the standout moment, drawing on that early Kinks melting pot of melody and aggression. The crowd grows throughout, stumbling serendipitously into the perfect launching pad for their Saturday night. Austra pick up the reins, battling on bravely despite, as frontwoman Katie Stelmanis tells us early on, all of their instruments having been ‘misplaced’ by their airline earlier in the day. If it was bothering them, they disguise it well. Recent album Future Politics dominates proceedings, with Stelmanis’ quietly furious political missives not interrupting the band’s danceable electro-glam. The more they played, the more the crowd drink it up.

Headliner Ellie Goulding draws easily the weekend’s biggest congregation, and its most eager to throw arms gaily into the night sky. Goulding repeatedly reiterates the historical importance of Latvia and Positivus to her career, which is honey to the eardrums of the crowd, but the pop uber-hits that are promised take a while to roll in. It doesn’t halt the ticker-tape explosions or the intermittent pitch-high shrieks from all around, but when the big ones do arrive, it leaves the crowd with nowhere further to go. Musical variety may be thin on the ground, but the massed ranks leave abuzz nevertheless.

Sunday’s runaway highlight is the irrepressible Eska, London’s most explosive powder keg of a singer. Her journey as a forty-something into sudden musical success has been one of the most intriguing and unexpected developments in recent British music and she is not going to let it escape - she has catching up to do after all. Her fierce, defiant songs are lightning rod calls-to-action for a Sunday afternoon, as she slides deftly from powerhouse R&B to gentle folk, her band as comfortable with dub breaks as they are with gospel drama. Every song brings a new mood, each one a winner. Eska has a direct channel to something powerful, the only question is how it took so long to become apparent.

Mew are European festival circuit mainstays by now, the Danes having been releasing their records for some two decades. They launch with one of their best-loved numbers, 2005’s ‘The Zookeeper’s Boy’, catching the audience off guard. Their prog-pop is as addictive as it ever was, and a perfect aperitif to alt-J’s closing night headline set. The Leeds band more than ever are ploughing their own furrow through the experimental outer reaches of indie pop music, with new album ‘Relaxer’ their most oblique and understated so far. It is, truth be told, probably not what the thousands in attendance have shown up for, but regardless, it provides some of the night’s high spots. ‘3WW’ and ‘Pleader’ are their most esoteric tracks to date, and both translate superbly to the grand stage. That said, old favourites ‘Tessellate’, ‘Left Hand Free’ and ‘Breezeblocks’ are what earned them this right, and those are the ones that bring the curtain down in grand fashion.

At a time when the festival industry is more competitive than ever, the UK’s entries have become congested, almost cumbersome. And yet a place like this is spacious and relaxed, how it was always supposed to be. In time, if more people get to know about places like Positivus, the scales might eventually balance somewhat. Don’t tell too many people, though.