Photo by A. Burakowski

This is the kind of warm and balmy Thursday evening where the temperature has dropped off to a more manageable 25 degrees at close to midnight. The patios of the bars that make up much of ul. Mariacka in Katowice are full, and I find myself in the bistro bar of Lorneta z Meduzą, pondering the joys of an establishment that offers pickled herrings, peppers, gherkins and cheese with shots of vodka. It's a fine mix and one that encourages civility, conversation and a great deal of fun, much like OFF Festival itself.

Now celebrating its tenth anniversary in tandem with the 150th birthday of Katowice, news of the eclectic mix of music and fantastic atmosphere offered by the OFF Festival has spread well beyond the borders of Poland. As evidenced by the any number of languages heard across the weekend, the reputation of the festival has drawn music fans from all over the world, hungry for an experience that's miles away from the standard of crowds being herded like cattle, insulted with poor food choices and eye watering prices, and subjected to sets from buzz bands unlikely to ever make it to their second album. No, this is a festival with a focus on a wide breadth of music, unencumbered by genre.

With temperatures averaging at around 35 degrees, the festival organisers have wisely not only ordered extra barrels of free water for thirsty mouths, they've also invited members of the local brigade to keep the soil at the Main Stage from completely cracking up, as well spraying those punters in desperate need of cooling down with powerful hoses. Even before a note of music has been played, it's manifestly clear that once again something special is on offer. With the food and drink area separated from the musical stages, the benches and tables laid out make the experience of consuming food and drink an event in itself, and one that offers the opportunity of meeting and talking with folk from around the world as well as Poland. And, contrary to its reputation as a meat eater's paradise, the selection of vegan and vegetarian food is wide and plentiful.

Friday's schedule starts over at the Trójka Stage with Władysław Komendarek. A former member of Polish 70s prog band Exodus, Komendarek specialises in electronic music that melds elements of techno with moments of progressive excess that all too often lacks focus. No matter because thanks to the compact nature of the festival – you're never more than five minutes away from any of the stages - it's easy to see something else. This, combined with the policy of having only two of the four stages presenting music at any one time, means that it's easy to find a compromise during the inevitable line-up clashes that occur throughout the weekend. So it is that sizeable chunks of sets by Young Fathers and Songhoy Blues are viewed without detriment.

Remaining at the Trójka Stage, it's difficult to watch Young Fathers without Massive Attack or TV On The Radio springing to mind. Not that this is to compare the sound of the bands, simply the fact that all three deal in high levels of originality. Young Fathers are certainly a compelling proposition and one fuelled by outrage and anger made all the more potent by having three frontmen sharing equal time centre stage. The rage starts as early as 'No Way' and it's with a heavy heart that I have to leave at the end of a devastating 'Rain Or Shine'.

In stark contrast at the Main Stage, Mali's Songhoy Blues are driven by an unabashed sense of joy that's utterly infectious. 'Al Hassidi Terei' sees the crowd erupting with delirium as the band's superb musicianship drives things on and the cheers, whoops and hollers at the end of their set are heartfelt and genuine.

By the time the sun begins to set on the Friday, former Bad Seed Mick Harvey revisits his love of Serge Gainsbourg once more. The setting of the Forest Stage, with its surrounding greenery and much needed shade proves ideal and with Harvey backed by a full band and a Polish string quartet, what could've been a predictable set is by turns lush and beguiling.

But if Friday night belongs to anyone, then it's Sunn O))). Easily one of the most anticipated sets of the day, darkness has enfolded the Forest Stage, which adds to the sense of menace and dread that accompanies their entrance. The dry ice that envelopes the stage and billows out into the audience is like the smoke from the Devil's own cigar but nothing can prepare the crowd for the onslaught to come. This is a festival that doesn't have to worry to about sound limits so when that first, downtuned and sustained note hits, the ground beneath feet actually shakes and this reviewer's shorts start flapping. A viscerally physical experience as much as an aural one, Sunn O))) flatten the place.

All of which conspires to make The Residents' headlining set on the Main Stage seem somewhat underwhelming. For sure, there are enough ideas on offer here – be it the continual anonymity, use of multi-media, subversion of music to name but a few - to dwarf most band's careers but such is the lingering effect of Sunn O)))'s uncompromising set that it becomes difficult to care whether The Residents are an example of avant-garde genius or simply a prank that's gone on for too long.

By contrast, Saturday's proceedings kick off in fine style at the Main Stage with King Khan And The Shrines. A glorious mix of soul, garage rock and a healthy dose of stupidity, they're an absolute blast dedicated to bringing the party under sweltering skies. They're a world away from Sun Kil Moon whose Mark Kozelek brings a mood of belligerence and drunken aggression to the Trójka Stage. Despite bawling out photographers in the pit and making abusive comments throughout while displaying his bloated stomach, this proves to be one of the most compelling sets of the weekend. As displayed on 'Clarissa', the dichotomy between the empathy at the heart of his storytelling and his wound-up persona is what makes it difficult to take your eyes and ears away from Kozelek.

Sun Ra Arkestra's explorations of the cosmos via free jazz and electronics on the Forest Stage are the stuff of hypnotic intrigue. 'Space Is The Place' is stretched out to a delightful groove that makes for the perfect accompaniment to the setting sun and by the time darkness has fallen the festival crowd is utterly seduced. Likewise, Xiu Xiu's performance of the music of Twin Peaks on the same stage breaths new life into Angelo Badalamenti's classic soundtrack. The trio of Jamie Stewart, Angela Seo and Shayna Dunkelman turn the music inside out while still retaining the haunting quality of the source material to offer something that's at once familiar yet startlingly original.

Ride's headlining set on the Main Stage is a revelation. Bolstered by a soundsystem that appreciates the benefits of volume, the reformed quartet are absolutely at the top of their game. Opening with 'Leave Them All Behind', the set builds through the wah-wah infusions of 'Polar Bear', a glorious 'OX4' and the wonky pop of 'Time Of Her Time'. Crucially, this isn't a band going through motions but one driven by a palpable urgency that's impossible to ignore. An elongated reading of 'Drive Blind' – complete with a full-on white noise freakout – gives way to a celebratory 'Mouse Trap' and the night belongs to Ride.

Broadly speaking, Sunday falls into two categories: the discovery of genuinely intriguing Polish acts and righteousness. Of the former, Coals and Innercity Ensemble triumph while the latter is dominated by The Julie Ruin, Algiers and Patti Smith Group.

Coals are Silesian youngsters Katarzyna Kowalczyk and Łukasz Rozmysłowski who between them make dreamy, ethereal pop music that straddles electronica with elements of folk. Coalescing Kowalczyk's beautiful voice and whispy melodies with Rozmysłowski's beats and languid synths, Coals are a band with the huge potential to cross over to an international audience. Though these are the first tentative steps that they're taking, the feeling that Coals are going to turn into something quite special is undeniable. This is a band to watch.

Over at the Main Stage, Innercity Ensemble are a collective made up of musicians from bands including HATI, Sing Sing Penelope and Quietus favourites Stara Rzeka and together they create one of the stand out sets of the entire festival. Part jazz, part psychedelia with a massive amount of improvisation, this is perfect music under a sweltering sun. By turns hypnotic and challenging, the audience is taken into a journey of sound that sees the group lock into a series of monster grooves and workouts that's met with a huge reception at the end of their set.

As with the rest of their 2014 tour, OFF Festival missed out on The Julie Ruin due to Kathleen Hannah's health issues but today's performance more than makes up for any disappointment. The band's spiky and consciousness raising punk pop battles through the heat that's built in the Trójka stage and there's a comfort to be had seeing Hannah back in action.

With the sun set over the Forest Stage, the highly anticipated Algiers deliver on their promise. 'Black Eunuch' explodes like a revivalist meeting, its urgency spreading through the crowd with haste while 'Claudette' sees the band's influences of gospel and post-punk seamlessly melding together. Guitarist Lee Tesche is a revelation as he coaxes all manner of unholy noises from his instrument that colours and fleshes Franklin James Fisher's impassioned vocals. Crucially, they sound absolutely massive and the rage at the heart of their music is convincingly conveyed to a rapt audience.

By the time Patti Smith Group take to the Main Stage, it feels as if the entire festival has turned out to hear the band revisit their debut album, Horses. Welcomed with love and affection by an audience hanging on her every word, Smith is part of that group of performers – seemingly declining in number – that believes in the power of rock & roll as a vehicle for social change. She certainly convinces tonight as she pauses to remember the victims of Nagasaki and consequently tears are freely shed throughout the audience. Received wisdom has it that Smith is a punk poetess but in truth she's the missing link between the hippy idealism of the 60s and what followed in the decade after. She still matters and, as evidenced tonight, so does Horses.

It's fitting then that Patti Smith sums up a weekend of diverse music, friendly crowds and an atmosphere that lives on in the hearts of those present when she declares, "You know what? I have to say that the OFF Festival is definitely on." The cheers that follow make it hard to disagree.