Anton Bruckner's Eighth Symphony is the last he would complete. He never lived to finish his Ninth (although he came agonisingly close to completing the finale, music that's still shamefully little heard in concert halls), so the Eighth is the summation of his symphonic journey. And what a summit the Eighth is! Bruckner himself said when he finished the work's gigantic, revelatory finale: "Hallelujah!… The Finale is the most significant movement of my life." Themes from all of the work's huge movements sound together at the end of the symphony, a moment that burns with what Robert Simpsons calls a "blazing calm". It's the end point of a 75-minute (well, up to 100-minute, if you're conductor Sergiu Celibidache…) symphonic journey, and it's one of the most existentially thrilling experiences a symphony has ever created. Bruckner's achievement is to make you feel, when you get there, that the whole experience of the piece is contained and transfigured in this crowning coming-together of symphonic space and time, and that the work's sublime darknesses - like the terrifying abysses of dissonance in the first movement, the kind of music that conductor Wilhelm Furtwängler described as Bruckner's "battle of demons" - and its equally transcendent light, like the climax of the slow movement, are simultaneously vindicated and vanquished by the sheer, breathtaking magnificence of this music, the last symphonic coda that Bruckner would ever compose.

But Bruckner's journey to the work's first performance, by the Vienna Philharmonic in 1892, was as tortuous as the music is (sometimes) serene. He finished a first version of the piece in 1887, and sent it to the conductor Hermann Levi, "my artistic father", who had already conducted the seventh symphony with huge success in Munich. Levi rejected the piece, saying it was basically unperformable; Bruckner was wounded, but returned to the piece to effectively recompose it over the next few years. And instead of the weak-minded naif who never got over people's criticism - as Bruckner is sometimes described - his revision amounts to a much deeper act of recomposition than simply answering Levi's concerns. The first movement ended in 1887 with a major-key triumph; in 1892, the audience heard instead music that winds down in minor-key desolation with a repeated, exhausted, death-rattle of a sigh in the violas. Bruckner himself wrote about this desperate moment, the only time in his life that he composed a symphonic first movement that didn't end with a fanfare of fortissimo power: "this is how it is when one is on his deathbed, and opposite hangs a clock, which, while his life comes to its end, beats on ever steadily: tick, tock, tick, tock". The other movements were also subtly but profoundly recalibrated; the effect is an intensification and sharpening of focus of Bruckner's musical ideas.

So all should have been set for the greatest night of his life at the premiere. And while the Musikverein was full of the great and good, including Johannes Brahms, Hugo Wolf and Johann Strauss, and with Bruckner's partisan supporters out in force, the naysayers were there as well. Brahms thought of Bruckner's works as "symphonic boa-constrictors", and the critic Eduard Hanslick - who left before the symphony's finale - wrote grudgingly, "In each of the four movements, especially the first and third, some interesting passages, flashes of genius, shine through - if only the rest of it was not there! It is not impossible that the future belongs to this nightmarish hangover style - a future we therefore do not envy!" Just as well he didn't stay till the end, Bruckner thought; he would only have become "even angrier".

Today, Bruckner's Eighth should still be controversial. This is a piece that is attempting something so extraordinary that if you're not prepared to encounter its expressive demons, or to be shocked and awed by the places Bruckner's imagination takes you, then you're missing out on the essential experience of the symphony. If you think of Bruckner only as a creator of symphonic cathedrals of mindful - or mindless, according to taste - spiritual contemplation, who wields huge chunks of musical material around like an orchestral stone mason with implacable, monumental perfection, then you won't hear the profoundly disturbing drama of what he's really up to. That unsettling darkness is sounded right at the start of this symphony. Instead of setting out on a journey in which the outcome is certain, in which everything is its rightful place in the symphonic, tonal, and structural universe, Bruckner builds his grandest symphonic edifice on musical quicksand. The Eighth starts with an unstable tremor of a semitone in the violas, cellos, and basses, which turns into a snaking, searching, chromatic collection of fragments. It's not so much a theme as a series of atomic musical explorations, and all of them in the wrong key. This is a symphony 'in' C minor, and yet in the early stages of the first movement, that home key is confirmed more by how much Bruckner avoids it instead of how much he inhabits it. You can describe the progress of this whole opening movement in terms of sonata forms and second and third themes and the other trainspotting jargon of the symphonic rulebook, but that scarcely relates to the experience of living inside this music, which is what you will feel happens when you hear it. One special moment to listen out for: the cataclysm at the centre of the movement that results in one of the emptiest, most desolate musical landscapes Bruckner, or anyone else, ever conceived: a single flute that somehow survives the onslaught to play a remnant of the orchestral tutti over tolling, funereal tattoos in the trumpets and chromatic sighs in the basses.

All of this intensity invites a search for meaning. Bruckner's music is open to our imaginations, and he even suggested possible interpretations himself for the symphony. In a letter to the conductor Felix Weingartner, he said that the scherzo, which comes second in this symphony (the first time Bruckner places the scherzo before the slow movement in a symphony) is a portrait of the figure of "German Michael", a bucolic rustic from German folk tradition. The somnolent, radiant, harp-haloed trio section of the scherzo depicts Michael dreaming, Bruckner says.

The opening of the finale is inspired by the Cossacks, as the Russians had recently visited the Austrian Emperor, to whom the Eighth is dedicated; this movement also features 'the death march and then (brass) transfiguration. Bruckner doesn't talk about the slow movement, but the adagio, the third movement, is the huge, generous heart of the symphony; a consoling, palpitating dream in D flat major whose opening is the closest Bruckner ever came to an evocation of the erotic; yet that bodily experience is transfigured into a blindingly radiant climax that seems to speak for the universe rather than mere individual figures.

Or maybe that's just me: you will make up your own mind, because the power of this piece can't be limited by any single interpretation, whether that's Bruckner's words, or the vision a particular conductor has of this symphony. But as you listen to that awe-inspiring but intimate, visionary but coherent finale - whose drama again can't be explicated by the crude pigeonholes of musical rules and regulations; instead, its "form" is phenomenological, something you just have to experience - I think you should hear the darkness as much as the "blazing calm" of the coda. It's in its acceptance of doubt, darkness, and despair that this symphony achieves its real glory. Bruckner's Eighth is an act of enormous empathetic consolation because it's unafraid to confront and to recognise sublime terror and darkness as well as light, Just like him when he wrote the piece, you need to feel engaged in that "battle of demons" when you're listening. Enjoy - if that's the right word!

Five key recordings

Herbert von Karajan/Vienna Philharmonic Orchestra: radiant and glorious, but opulently terrifying too.

Wilhelm Furtwängler/Vienna Philharmonic Orchestra: protean, ever-changing, symphonic molten lava. Bruckner as daemonic inspiration instead of cosmic consolation.

Staatskapelle Dresden/Eugen Jochum: Jochum's idiosyncratic interpretation, with a remorselessly swift first movement, gives a unique shape to his performance.

Munich Philharmonic Orchestra/Sergiu Celibidache: on the face of it, Celibidache's glacial speeds are borderline bonkers - the slow movement alone lasts more than 35 minutes! But is there a performance that makes you feel space and time are dissolving into each other in the coda of the finale as much as this one? Stick with it and see what you reckon.

Georg Tintnter/National Symphony Orchestra of Ireland (1887 version): Tintner makes the case for the original conception of the Eighth: not so much another version as another symphony.