I couldn't resist a quick jaunt to Reykjavík for the first ever Icelandic edition of the famous Sonar festival. The chance to see some of the very best stuff Icelandic music has to offer in such a short space of time was too tempting. I had never been to another festival here other than Airwaves, so I was keen to see the comparisons.

The obvious stuff – everything official was happening on one of the four stages in Harpa. The two great rooms we're used to at Airwaves plus the underground car park converted to a club area and the ground floor 'bay view' area which was a neat idea but really struggled for atmosphere. Apart from a good line-up at Volta (FM Belfast, Legend and others) there was very little happening off-venue.

The audience at Sonar was much more Icelandic, I reckon at least 80% instead of around half at Airwaves. There also seemed to be more extremes of age, definitely a large contingent of under 18s and a good scattering of 60+. There was more bad-temperedness on show than I've seen before, a couple of shoving matches happened when people took exception to those guys (you know, those guys) who want to march up to the front of the show using shoulder barges as they go.

The music for Sonar is described as cutting edge, certainly everything in Reykjavík from overseas could broadly be classified under 'dance'. The selection wasn't that straightforward for the local acts, the more obvious choices like GusGus, Retro Stefson, Samaris & Soley were joined by acts like Sin Fang, Mugison & Asgeir Trausti – I was interested to see if that second batch of acts would adapt their shows.

Almost half of the acts playing were DJ sets, and whilst I know there's skill involved in this it remains really hard for a bloke playing records not to look like a bloke playing records. I know, I don't get it. I mainly avoided these sets but did enjoy what I heard at sets by Human Woman and Pedro Pilatus. What I got, as I look back at Sonar, was a bunch of very fine shows (headed by Samaris [right], Valgeir Sigurdsson, Bloodgroup and Soley – those last two had to struggle in that weird non-gig space of the bay view area) and six really exceptional ones. The final score, not surprisingly (have we met?), being Iceland 5 Rest of the world 1. Let's talk about them…

Ghostigital's set was excellent, of course it was. It was a shame that it started in front of such a sparse room, luckily the noise (oh the noise) drew a decent crowd in pretty soon. This is something Sonar had in common with Airwaves and Icelandic nightlife generally – not much is busy until at least 10pm. This was the first of many sets to be conducted exclusively, or nearly so, in Icelandic. Fair enough too, these are Icelandic people in Iceland – I guess I'm so used to hearing English at Airwaves where the crowd is so much more international. Of course, Einar makes most of his lyrics up on the spot so these were all Icelandic too. It doesn't matter one bit to the overall effect, I just don't get the jokes! Ghostigital triumph through that wondrous, thunderous alignment of beats, voice and extreme volume – Harpa passed the volume stress test that some other venues have failed. Highlights, if I'm coping without the English language prompts were Hovering Hoover Skates and Numb.

The late night Friday slot produced a choice between local legends GusGus and the ever growing reputation of Retro Stefson (I CAN NOT BELIEVE it is 7 years since I first saw this band, and they are still so young!). In the end, the choice was removed, the queue to see GusGus was extraordinary (I assume due solely to the excellent endorsement in the Grapevine) and so my plan of catching half of each set became a full blown party with Retro Stefson. Party continues to be the word for these guys. They’ve changed a lot musically over the last 18 months, but even this slightly (you should have seen them before!) toned down live approach still manages to get every room they play in jumping like lunatics. Like at Iceland Airwaves their set concentrated almost exclusively of the newer sound of their most recent record, highlights were littered throughout the hour they spent with us but the renditions of Glow and Qween were my picks. The very best was saved for last – I was so pleased (and they definitely were) to hear them go right back to the debut album for a good 10 minute rendition of Senseni. Total and utter triumph.

So the first night produced two huge ticks. The Saturday night doubled that tally, and also had another increasingly confident outing from the very fast improving Samaris, who wowed a big crowd in the Silfurberg hall. In what must be the all-time record for earliest start to a Saturday night in Reykjavík, the first show of the evening was at 18:30. Of course, Ólafur Arnalds was well worth heading out early for. The Norðurljós hall had been fitted out with rows of seating and the crowd in the full venue sat in the type of stunned silence that Ólafur must be very used to by now. It was every bit as great as the Airwaves show in the same venue months earlier. My personal highlights this time were a perfect version of Near Light and the two collaborations (Old Skin, and a track from Ólafur’s very imminent new album) with Agent Fresco vocalist Arnór Dan. This was the first time I have seen Ólafur perform with a live vocalist. Bring on that new record, and (whoop!) the show at The Barbican in London next month.

Shocking news. I loved a set that wasn’t by an Icelandic band! The fullest room I was a part of at Sonar (I wasn’t at GusGus, Modeselektor, Simian Mobile Disco or LFO all of which I was told were rammed) was in Silfurberg to see James Blake. I was really intrigued to see this show. James won a lot of friends in Iceland a few years back when he really threw himself into the spirit of Iceland Airwaves, popping up all over town for impromptu sets and, let’s face it, drinking into the small (not that small) hours. Knowing that and hearing talk around the blogosphere of an upcoming and reputedly sensational second album convinced me to venture “non-Icelandic”. What a good decision, this was an exceptional set of clever beats, soulful tunes with some cracking singing and effects and came complete with a proper screaming at a pop-star moment (not me, waaaay too cool) when he began to play Limit To Your Love. I have no idea what genre label you’d put on this type of thing. The real star for me was the drummer who, for a couple of hours, came close to getting ahead of Mugison’s drummer in my drummer-based affections. There’s a lot to hate about James Blake, he’s good looking, incredibly pleasant and unreasonably talented. Try as I might though (!) I absolutely adored his set, and I can’t wait to hear the new record and see more shows.

I’ve already been a bit rude about the Bay View Area more than once. It didn’t really work out. Half the time it was half empty, all of the time there were people eating their dinners not that far from the stage. The lighting (and Harpa has the best I have ever seen) was odd, with a permanent pair of bright lights pointing out at the half-blinded crowd. Sin Fang was the exception to the rule. Sindri and his mates played a set of songs from brand new (and utterly wonderful) album, Flowers. It must just have been those songs that made this set so enjoyable. Once again the ‘area’ was sparsely populated. Nobody had dared venture within 5 years of the stage, then a few rows of people sitting on the floor and finally people sitting around round table wondering if they are at a concert or in a café (answer: both). Sin Fang have just made a wonderful album of songs I want to hear over and over again, and they get even better heard live. From the Strokes-like “See Ribs” through to the very charming “Young Boys” and “Sunbeam”, every track is a winner. I could watch this band every day right now.

Sin Fang didn’t seem to vary anything about his set of songs in a nod to the Sonar ethic of dance or cutting edge sounds. That was fine I loved it, but it was noticeable that Mugison, my final highlight, did go a little bit ‘fusion’ – his word, not mine! Mugi’s set-up looked the same as the show he played at Airwaves but with the addition of what I think we need to call the ‘mirstrument’. I can’t describe it, it is an instrument that makes all kinds of noise and I suspect only Mugison really knows how it works. This was a very different set to the one in November. I was delighted to hear him start with a pair of really old (a decade already?) favourites, “Poke A Pal” and “Sea Y” and then later on, “I Want You”. Even the standard, ever-present songs in mugi-sets like “Mugiboogie” and “Jesus Is A Good Name To Moan” were transformed by the box of tricks. And, my God, the traditional set closer “Murr Murr” which has already had many iterations since its launch as an acoustic lullaby, once again was transformed. This time it became something thunderous and terrifying but still retained THAT riff somewhere in its soul. An incredible end, I had to go outside after that to check the world hadn’t actually ended, because it sure sounded like it might have done.

So yes, I am glad I was at Sonar Reykjavik. It isn’t Airwaves and it was never going to be. I missed the rushing around the streets because there’s JUST TOO MUCH going on all at the same time. I love Icelanders (yes I do!) but this festival lacked that spirit that I guess a bunch of foreign music lovers adds to the city. Having said that, at Airwaves time that’s pretty much all Reykjavik is about. These last few days it has been nice to see RVK going about its normal business, mainly unaware that cutting edge music has arrived in the harbor. The truth is of course that cutting edge music, and all manner of non-sharp edged music of extraordinary standard, is always present here, part of the soul of the place. It’s just that these festivals are the best way to let the rest of the world in now and again. More, more, more.