I ONCE vowed that I would always embrace new music, that I would never become like those guys who got so set in their ways that they listened to nothing but 1977 punk or 60s pop.

Somewhere along the line I dropped off the wall though, plugged deep in an (albeit excellent) mire of 90s rock and metal.

Along the way I enjoyed some new tunes, but for the past couple of years I have constantly returned to somewhere between 91 and 94 with Pantera, Alice in Chains and Tool.

Fortunately for my fellows I've managed to confine it to this and avoided a Madchester bowlcut and bad fluorescent hoodies.

Still, it has become the aural equivalent of slippers and a pipe, and I really need to slap myself.

Thankfully, for the first time in donkeys, mules and asses, I have levered myself out of my musical swamp with an album which I actually think I'll be listening to in ten or twenty years time.

I can't remember exactly what inspired me to get Mastodon's Crack the Skye.

They're a band I've liked since their bludgeoning debut album Remission back in 2002 when the riffs of March of the Fire Ants strayed in front my metal radar.

Then they were certainly different. Complex, rat-a-rat rhythms, sludgy yet completely hook-laden riffs and enough esoteric nonsense within the lyrics to keep me interested.

Since then they have joined the unholy trinity of bands who have managed to bring prog-rock to the masses, alongside Tool and The Mars Volta.

Having combined an overarching run of thematic devices over their run of albums - Fire (Remission) Water (Leviathan) Earth (Blood Mountain) - they have also gradually gotten...er...madder with their concepts.

Leviathan was, for a modern metal album, inspiringly brave in using Moby Dick as a source material.

Combining sheer heaviosity with some subtle melodies, the album brought in a wave of fans. Blood Mountain came up with its own story of the search for a fabled Crystal Skull on the said mountain.

Now, with Crack the Skye, we have untamed prog. With themes on both a storytelling and genuinely emotional level (namely Rasputin, a disabled boy, wormholes and the suicide of drummer Brann Dailor's sister at 14) no one can accuse Mastodon of being one-dimensional. Someone may have indulged in some extra-curricular recreation, who know...

Indeed, they are brave in giving little consideration for the fans of the older, sludgier, screamier material.

Only a couple of parts of Crack the Skye have heavy vocals.

Mostly it is ethereal, with harmonic vocals layered over intricate, stunningly constructed waves of overlapping complexity.

It is to their own testament that the songs don't become muddied in the sheer muso-excitement of the likes of four-parter The Czar or the 13-minute The Last Baron.

Crack the Skye is the band's ether album - four out of the five aimed elements.

And the spacey qualities are there for everyone to see.

The guitars are certainly more 'rock' than previous outings, something which has led to the usual boring cries of 'sell-out'. Well, if this is a sell-out the gods know what the brats of the pop-pack will make of the future of music. Hopefully they run screaming.

Far from being a case of selling out, Crack the Skye sees a band reaching to extend itself in all aspects of its art. Managing to maintain a sense of musical experimentation, emotional reach and metal intensity is hard.

But Mastodon have touched that pinnacle. Can they go on to reach greater heights?

Come see me in a decade.