You often hear that the people of Lisbon love to party, NOS Alive is proof of that, for a few days it sits in the heart of the city and bounces music off the nearby houses - local residents seemingly happy to have The Prodigy rattling their windows in the middle of the night. To be fair the local residents are all seemingly at NOS Alive dancing to The Prodigy and having the time of their lives.

The festival spreads across six stages, although one is purely for the benefit of those queueing to get in - the ethos appearing to be that time not dancing is time wasted - and one is a comedy stage, which becomes space for a surreal breather for non-Portuguese speakers like myself. It's housed on a relatively small site, yet sound bleed is only an issue between songs or when Mumfords decide to do the really emotional number, mainly because it's the loudest festival I've ever been to.

The first band I saw were The Wombats, who appeared to be winning over the crowd with dad jokes, after seeing them, their popularity remains utterly fascinating to me. They make the musical equivalent of a kid chasing after a bus that is leaving the station, the piss weak bubbly lager of boring indie, probably the best selfie stick of our disposable culture.

Young Fathers are a different kettle of fury entirely - they are a genuine proposition, engaging, challenging, and ultimately as thrilling a live band as you will see. They rattled through their set with minimal fuss and chat, staring down the crowd, begging them to blink first, each member taking a turn to cheerlead at centre stage. At times all four of them are writhing and flailing as one, seemingly becoming one organism as they harness their own righteous noise. Early punches faded into a mid set breather before the fire returned, but even in the downtempo moments the message is clear. Young Fathers hold a mirror up to our collective action - it is confrontational, but they seek to inspire you to action when no-one else is really saying anything, it's a call to arms from the most exciting band on the circuit at the moment, and they have the songs to make you want to listen. The power of their set made it cruel for anyone following them, I drift through Metronomy's set without any of it sinking in, aware of the dancing and the smiles around me - still floating in the wake of Young Fathers.

That said, when I left the site it was the music of Alt-J that I had swimming around my brain. It's funny how perceptions of a band can change, because from a distance the careers of Alt-J and Young Fathers have taken similar trajectories, both won the Mercury Music Prize with their debut album and then followed it with an album that didn't make obvious choices. Yet Alt-J stumbled upon widespread popularity, at the same time as they were being rejected by the hipper than thou tastemaker set, Young Fathers have been revered for their choices as they slow burn to their success. It would've been easy for Alt-J to chase popularity, but with This Is All Yours they chose to drift further into the depths of their own idiosyncratic musicianship. I guess some people only root for the underdog. Songs like 'Tesselate' and 'Matilda' sound incredible from the main stage, and whilst the band are still growing into performers that can captivate from stages of that size, their music certainly suits the setting and they are definitely not underdogs anymore.

The bands don't start at NOS Alive until late afternoon which allows them to clean away any evidence of the night before and gives you time to explore the city or recharge without missing anything. Each day you return a little more familiar with the site. The format means you get three chances to return fresh to the scene of the crime and perfect your party.

In my review of Wilder Mind earlier in the year, I mentioned how Mumford and Sons weren't being very smart when they started renouncing the banjo in interviews, because they'd have to continue touring their banjo led songs live for the foreseeable - which they have, and they certainly don't seem to be playing them any less passionately. It's just that the newer songs work better in this environment, they are fit for purpose, more suited to the main stage. Where previously they used quiet and loud in every song, stop/start, they now plod. A mid tempo plod with a repeated chorus refrain and small crescendo, perfect for the big crowds, a steady pace works better for the guy at the back who had previously only just started to react as the loud rousing chorus faded back to Mumford and his acoustic guitar. Mumford and Sons get criticised a lot because it's easy to punch up at the big guy, it's easy to only champion underdogs, but there are very few bands who have adapted to headlining venues/crowds of this size so well and they don't seem to get credit for that. It's something that Alt-J will be working out this summer on their first go-round on the big stages. Assessing what works and how to present yourselves at a headliner level is a completely different sport to just turning up and making sure your guitar is tuned.

It's a good time to mention the big screens, a personal gripe: please, for the love of all equal humans under heaven above, please, stop with the endless girl cam. It's 2015, but in any time - predatory camera men constantly searching the audience for pretty girls to share with all the other boys - it's rank. By all means show crowd shots, by all means show individuals having fun on the big screen - individuals lost in the dream of great music - but to go from band to random girl to band to random girl constantly - it means that it was the brief. Stop that, it's not necessary, please, just stop that.

Omnipresent festival band Future Islands are a vehicle for Samuel Herring, a whirling mess of vowel sounds and trademark dance moves that draw cheers almost as big as the songs - but it's like my friend said to me, as many people know David Byrne for being that guy in the funny suit as they do for being a musical genius. If the end result is that people are listening to Future Islands I don't see why I should care. They are the perfect pop blend of melancholy and uplift - perfect for dancing at a festival with friends because boy when that music starts you better know you are intrinsically alone, Future Islands are a hand that reaches down and helps you up and out. They are the knowledge that you are not alone, or rather, we are all alone together. There is nothing more beautiful than sweating out the worries with a crowd of smiling strangers. They play an extended run of old songs in the first half of their set that shows they are more than one album, 'Long Flight' and 'Tin Man' stand out, but it's their latest single 'The Chase' that provides the moment of realisation - this band are only going to continue getting better and better.

Many of the best things in life come from acts of spontaneity, doing an about turn and heading into the dance tent when you hear 'Gangsta's Paradise' because you've had too much to drink and whatever - seemed like a good idea at the time - don't make me justify it now - oh god - don't judge me - don't judge me - was one of those things. Bouncing around rapping really badly to cheesy music from the '90s whilst inebriated is as good a definition of fun as you're likely to find. As is spending the next few hours dancing with a group of strangers who treat you like an old friend. The point is losing your inhibitions, letting down your guard and just being free to have fun - these things seem to be natural for the NOS Alive crowd.

The thing is, you're missing the point of being at a festival if you only see and do things that you've done before, even more so if you go to a festival in Portugal and only see UK based bands. Dead Combo are a great example of this, they took me from killing time to heavily engrossed in the space of a song. Two guitarists, two percussionists, and a hell of a journey. Their music is a mix of Fado and post rock, which makes for a mournful slow burning soundtrack to the best western movie never made, one that occasionally erupts into bouncing and party. If they were signed to Constellation they'd be your favourite band.

I could've written a review of Mogwai's set without even seeing them play it, they are dependable, they are constant. They will mould you into an existential funk over the course of their set, within each song, with their peaks and troughs and "obrigado, thank you's". You can depend on Mogwai, on what they do, the difference is you. The ever changing reality of your existence is what determines how you experience their music, how you interact with their constant, where your head is at when you collide with them. So watching them on a Saturday night, after exploring the beautiful and historic city of Lisbon all day, is probably as good as it will get for me.