GLASVEGAS: The best Scottish album ever?

But, even in this age of the internet downloader and music industry doomsayer, an album is an album - and that's how you'll be judged. Amidst such critical clamour and fan anticipation, it's remarkable that Glasvegas have released an instant classic, a five-star slab of sonic perfection, a seminal Scottish album of such passionate intensity that it will make grown men weep even as it makes their ears bleed. Yes, it really is that good.

"When I read the lyrics and listen to the music, it's such a euphoric thing," Allan tells me, "because I've achieved the thing that I wanted to achieve. I just wanted to get the world that I'm living in down on plastic. After finishing the album, when I had those poems and the audio in front of me, I knew I was totally true to that place."

That's the sound of a man happy with the end product, as well he should be. Glasvegas are a four-piece - singer Allan, his cousin Rab on guitar, Paul Donoghue on bass, Caroline McKay on drums - but their vision belongs to Allan. He's the one who writes lyrics - his "poems" - about tough life in working-class Scotland, then fits these dark, very personal words to sweet melody lines that themselves are set against a wash of guitar noise and drum beats that crack like gunshots. It's a starkly textured approach to songwriting that, on the new record, works equally well for the tracks individually and the album as a whole.

The shimmer of guitar distortion that slowly rises from the speakers at the start of Flowers & Football Tops provides an overture of sorts, before Allan sets the album's expressive agenda with lyrics filtered through the eyes of a mother who has just been told her son has been murdered (the song was partly inspired by the violent death of Glaswegian teenager Kriss Donald in 2004). Towards the end of this seven-minute opener, with two minutes still to go, Allan gives the first indication that he's no ordinary songwriter, but someone with exceptional musical and emotional depth. Taking the old standard You Are My Sunshine, he twists a word here, misdirects a chord into minor there, and turns an over-familiar ditty into a poignant, plaintive cry from the heart.

"It can be quite painful doing these songs all the time," Allan admits. "I always try to make sure I'm thinking about what I'm saying and that the words aren't coming out on autopilot. I always try to think about those people. As an artist, the most important thing is what you're saying - and saying it with the same authenticity or sincerity all the time. The baby' part of that song Flowers & Football Tops - Baby, why you?' - that's just total frustration, total confusion at how f***ed up life is."

The pace lifts as Flowers & Football Tops segues straight into hit single Geraldine, and it in turn cuts into the album's standout track, It's My Own Cheating Heart That Makes Me Cry. A few songs further down the line, we come across Go Square Go and current single Daddy's Gone - Glasvegas haven't kept off the album any of those songs that have been doing the rounds for over a year now. As such, it's a full documentation of the band up to this point. But, crucially, they have re-recorded their earlier efforts, giving a sharper edge to the guitars and a more thunderous roll to the bass. In other words, they've added testosterone to songs that already were the dog's bollocks. Only Go Square Go is less punchy than its original version: with its naked aggro and "shoobie-doobie-doo-wahs" removed, there's more emphasis on it as a proper song rather than a crowd favourite famous only for its "Here we, here we, here we f***ing go" belter of a chorus.

Erasing some of those poppier 1960s backing-vocal affectations is probably a smart move: it makes Glasvegas seem less gimmicky and less reliant on Phil Spector's big bag of production tricks. It also means that all the songs sound as if they've been created at roughly the same point in time, not been spread from then to now across the band's career. In this way, tried and tested favourites don't overshadow songs newly written and recorded for the album. In fact, if anything, it's the tuneful vocal lines of Lonesome Swan, Polmont On My Mind and SAD Light that stick in the mind, suggesting that Allan has an instinctive skill as a songwriter beyond the unique, ear-grabbing production sound of Glasvegas's debut album.

And then there's Stabbed - two minutes and 22 seconds that raise the album from rock classic to art work. A life-or-death plea delivered at the wrong end of a blade in a street fight, it places Allan's striking deadpan vocals in a big, echoing room, accompanied only by a piano playing Beethoven's Moonlight Sonata. The effect is devastating, like a black-and-white short suddenly projected in the midst of a battery of widescreen colour features. This is the album's purest moment of musical beauty juxtaposed with its urban harshness.

Although the 10-track debut ends with Ice Cream Van, this closer could be considered a coda or even, if you set your CD player or iPod on repeat, as the atmospheric link that takes us right back to the guitar shimmer of Flowers & Football Tops. In musical terms, it's not too lofty a claim to call this album a song cycle: it has a beginning, middle and end, a consistent mood, and it has been carefully thought over by its creator then crafted further in the studio. Allan's goal, particularly in a song like Ice Cream Van, is much more down-to-earth than such critical pretensions, however.

"I can't believe how much that song takes me to the street that I grew up in when I listen to it," he says. "And that's what I was trying to achieve with this album, with the audio and the poems. It's such a domestic thing, such a human thing. I really want to be there, sitting on that pavement, when I'm listening to it."

Organising these vivid images into a succession of perfect musical moments was no mean feat. There were times during the recording of the album in the US earlier this year that a despairing Allan wondered if he would ever be able to communicate his inner thoughts to the outer world.

"We were in a studio in Brooklyn," he remembers, "and it was probably a lot more isolated than people think. I mean, there were some mad nights that we had in New York - the rock'n'roll side of things - but a lot of the time it was quite isolated. There were times I doubted I'd be able to get those colours and melodies onto the plastic. I went through the whole self-doubt thing. When we were in the studio, I could have been anywhere in the world; my head is out in the f***ing Milky Way anyway when we're making music."

The odd, alienating experience of being far from home eventually gave him the necessary distance to put his ideas in order. He even recognised that there was a universal element to his personal stories.

"Some nights, man, if you can imagine, when I was walking home from the studio really late, just walking through the streets of Brooklyn ..." he drifts off into the memory. "It made the world seem really small because we took our world, our songs, from Glasgow to New York ... and I was walking home, thinking about the things I had been singing about, the things that had been on my mind, walking through the streets realising that, although I was in Brooklyn, it's all the same thing. People are people, there are cars going by you, there are people in the streets. It could quite easily have been Glasgow. I'm basically trying to say, my wee world in Glasgow, and then when I was in Brooklyn ... we're all the same, really."

Perhaps it's this difficult-to-express-but-simple-to-experience factor that helps Glasvegas connect to the public to the extent that they can have a number 16 hit in Geraldine and know that Daddy's Gone will crash into the singles charts today. That and the emotional honesty that Allan brings to his songs.

"I'd never even thought about chart positions before," he insists. "The way I see it, whether a thing is a hit or isn't a hit, the most important thing is that I can get a good sleep at night knowing that I gave myself away to the song and the music. What I was actually trying to say in the music - that's more important than chart positions."

Maybe so, but that's not going to stop me naming Glasvegas as the album of the year so far. And any moment now, I'll be heading down the pub to kickstart the debate, laying out the evidence as to why a debut release can indeed be an immediate challenger for the title of best Scottish album of all time.

Glasvegas play Fat Sams, Dundee on Wednesday; QMU, Glasgow on Friday; and Liquid Room, Edinburgh on Sunday. Their debut album is released on September 8