Sufjan Stevens’ concert at the Sydney Opera House last month was a dream fulfilled, a celebration, a journey into space and sound and color, an ecstatic revenge of the nerds, with go-go girls and balloons.

I’d been waiting years for this (as I mentioned in this ode to Sufjan written the day of the gig), but my timing was just right. It was one of the best shows I’ve ever seen, thanks to the synergy: a musician at the peak of his powers, perfect sound, a warm and adoring crowd inside an iconic edifice.

On his new album, The Age of Adz, Sufjan blasts into uncharted nebulae of orchestral weirdness, electronic beats, visionary raving about pain and too much love and murdering ghosts, supernovas of obsession and heady sonic invention. He sings about Mount Vesuvius, mixes up the pronunciation with his own name. It’s about creative energy spilling out, the fire of emotion, the destruction of self, the end of the world. Maybe not in that order.

Eno, Bowie, Zappa, Björk, Stevie Wonder, Joni Mitchell, Danielson, Flaming Lips? Animal Collective? TV on the Radio? Uh, Beatles? There are touchstones, but it’s hard to keep track; Sufjan has a way of incinerating his influences and scattering the ashes. The album’s raising eyebrows, making new fans. He sold out the Concert Hall at the Opera House, twice. Then sold out the State Theatre. It’s a beautiful thing when an artist decides to get really weird, only to see their popularity go on rising.

As 2671 (or so) delighted people greet Sufjan when he takes the stage, no doubt the question on their minds is, how is this weirdness going to come across live? The answer is meticulously plotted and arranged: 10 musicians are scattered all over the huge stage. Two drummers, brass, backup singers, more keyboards than I can count. But the operatic acoustics combined with Sufjan’s perfectionism as a bandleader make for awesome sound: each instrument balanced in the mix, the arrangements complex but warm and visceral, vibrant, colorful.

Color is a big part of Sufjan’s new vision. He and the band and their instruments are plastered with day-glo accessories and florescent electrical tape in wild future-tribal patterns and shapes, glowing matrices, like a Tron Mardi Gras. The light show and video projections are all color and geometry and science fiction, including the work of the paranoid visionary artist Royal Robertson, a major influence on the new album.

So the band is gathered, the fuel loaded, the colors primed, and we’re ready for a ride into the dark electric heart of the new material. So it’s a surprise when they start playing the melancholy opening to the title track of 2004’s Seven Swans, a mostly acoustic meditation on mystic-Christian themes. But as the song gradually builds in intensity, we’re reminded that its lyrical allusions to the Biblical Apocalypse, its slow-burning orchestral climax and its swooning haunted chorus make it an early harbinger of The Age of Adz. It’s actually a perfect preface.

Pulling us in with a classic, Sufjan then launches into the single “Too Much,” one of the brightest and biggest of the new songs, the meta-pop video projected huge over the stage, and we’re off. The rest of the show will be almost entirely new material, and powerfully effective it is. The baroque/folktronic sound is wholly integral, somehow avant-garde and arena-ready at the same time – it feels like a new paradigm. The intricate arrangements, the buildups and breakdowns, the many changes of the sprawling songs are played with grace and aplomb by the garishly-outfitted band. The new album, which I had considered kind of difficult, starts to come to life for me.

As each song ends, the applause becomes louder, the whoops and whistles from the crowd more shrill and enthusiastic. This is a great cross-section of unpretentious Aussie fans – some of them in their class-A hipster uniforms for the Opera House, some not dressed up at all, swilling champagne in their trainers – and they’re right there with it, loving it. There’s something about Sufjan that all kinds of people connect with. It’s pretty gratifying to see someone so nerdy and utterly himself win affection from the punters.

When he talks between songs, he has a good deal of (nerdy) charisma, but also an utter sincerity. And a rambling pressured way of talking, like he’s thinking too fast, imagining things, trying to find ways to share what he sees with the rest of us. He tells us how amazing it is to be playing in this, this spaceship – over and over he calls the Opera House a spaceship – and says he’s so happy to be in Australia, such a warm place, he can feel the warmth in this room, the warmth of beating hearts, the warmth of love.

Something about his presence feels like a challenge. Am I living up to my potential, being creative enough? Speaking freely enough? Striving hard enough to share it with love? I’m filled with an acute urge to go out and create and live every moment of my life.

I’ve been a fan of Sufjan’s for years but didn’t notice until this night how good a singer he is. His voice is reedy, and twee, yet surprisingly strong, and he has a lot of control over it. The concentration, the obsession he shows when performing is captivating, and the emotion and poetry within shine. He sings,

When I die, I’ll rot
But when I live I’ll give it all I’ve got
Gloria, gloria, it rots
Victoria, victoria, it lives in all of us

and the place is absolutely hushed, his choral falsetto swirling around the spaceship cathedral’s rafters. How can music be so melancholy and euphoric at once? Sufjan tells us the tune is about the end of the world. But don’t worry – it’s going to be OK, it’s all going to be OK, we’re not going anywhere. He says it with conviction.

The set list flows, epic overload freakout followed by quieter stuff in the aftermath, just his voice and one or two other instruments. “Futile Devices,” a brief acoustic number on the new album that harks back to Sufjan’s earlier work, becomes a highlight. Chiming, ringing, plucked strings, simple piano playing, Sufjan tenderly confessing to a friend that he loves her (or him?) but can’t say it out loud. With the Concert Hall hanging on every word and note, Sufjan is quietly, slyly approached from behind by a bearded, face-painted space traveller in mirror shades – a keyboardist – holding a little Casio up to the mic, finishing off the little tune with a low-fi electro-jazz improv. It’s so melodic, such a perfect interface between folky and futuristic, heartbreaking and hilarious. The crowd erupts into boisterous appreciation. Tears form in my eyes.

Shortly after this it goes completely electro, big-beat, kicking out the jams, the backup singers become plastic-and-silver-nylon-clad go-go girls, as Sufjan sings, I must do myself a favor, I must get real, get right with the Lord. He gets us up to dance and clap and sing along, and the Sydney Opera House has become a cross between a hootenany, a church revival and a rave. It earns him his first standing ovation of the night. Sufjan – applauding the crowd right back like a high-school music teacher – can do no wrong. He announces he will now play a 25-minute tune, and everyone smiles and claps some more as if he’s promised free champagne. “Impossible Soul” takes the show into hyperspace, and all over the place, with Reichian experimentalism, Flaming Lips-esque prog-power-pop, Autotune R&B stylings, the stage transformed with screens and partitions and light, costume changes and – finally – a folky conclusion. No one gets bored. Boy, we can do much more together – it’s not so impossible.

Another standing ovation. The call for more is long, loud, amazed, heartfelt. When the band comes back out, it’s time to come back to Earth and simply celebrate, and sure enough they’re playing “Chicago,” and balloons – balloons! – thousands of balloons are pouring from the rafters, bouncing all over the hall, volleying back into the air, getting knocked around by the crowd, the climactic power of the anthem subverted, replaced by the childlike glee taking over the place. Sufjan singing, I made a lot of mistakes, I made a lot of mistakes, like we have a right to be this happy all the time.