Cloud City had brought a crowd with them: friends, fellow travelers, supporters. Problem is, frontwoman Sarah Martin payed too much attention to them at the expense of the other people in the room. At times it felt like a party where a bunch of friends had decided on a whim to set up a P.A. and belt out a few tunes, cracking jokes in between songs for the benefit of their friends. Great fun when you're playing a party for shits and giggles, but not how any band should play a gig at a venue where people have payed money to see them.

But crowd interaction aside, Cloud City keep it simple: they've got their sound and style worked out, and they don't try too hard to be anything they're not.

Martin's effortlessly powerful voice soars above the grungey hard rock foundation layed by her straightforward, understated guitar playing, and a highly melodic rhythm section - featuring the impressive Ross Koger on bass - gives the music its depth. I don't want to say the music would be dull if it weren't for the bass and drums, but the rhythm section is clearly what makes them shine.

Perhaps they would be more fairly judged after hearing a recording, but I found that too many of their songs languished in similar tempos and identical structures.

Interstate visitors Nucleus took what seemed like an hour to organise their rather gargantuan stage set-up: one and a half drum kits, three microphones, two candelabras and countless stomp-boxes and effects units were among the equipment they used through their set, and as I found out, none of it went to waste.

Guitarist Dylan Mitrovich took his place on the left with a guitar, a vocal microphone, a dozen or more guitar effects, and even a mini drum kit; Mark Tyson's drums were augmented by an electronic kit and sampler; and to the right, bassist Ayden Mitrovich carved out a space for himself surrounded by an arsenal of basses and effects. In the middle was lead vocalist and guitarist Matt Quayle, flanked by two ornate six-foot candelabras.

Having heard both of Nucleus' EPs in the past, I thought I knew what to expect from their live show. Turns out I had no fucking idea. Ayden Mitrovich kicked things off by screaming "good evening Revolver" at the top of his lungs, unaided by a microphone, and for the next 40 minutes I forgot where I was.

A brooding atmospheric soundscape introduced their first song as all three guitarists flowed back and forth, their backs to the audience, like warriors psyching themselves up for battle. As they exploded into their first song, brimming with energy, it was clear this was not going to be an ordinary rock show.

I can't even compare them to another band in terms of movement and energy on stage, because I don't think I've ever seen another band quite like them.

Musically they are reminiscent of Tool in their heavier songs, but they compliment this side with a more atmospheric, almost post-rock sound, which makes them difficult to categorise.

Three-part vocals and layered guitars give their heavier songs incredible mass, which is only increased when Dylan Mitrovich plays the part of a second drummer.

By contrast, their melodic post-rock side seems just as well developed, and forms an integral part of their sound as a whole. Their brilliance as a band has most definitely not translated well onto their EPs, and that's not to say the EPs are anything less than stellar, they were just so great live.

Clearly, Alaska Ratio had their work cut out for them trying to follow such a band.

Compared to Nucleus' mountains of equipment, Alaska Ratio went on stage naked: just three guys, one guitar, one bass guitar, and one drum kit. Their music was therefore much less complicated and more focused, sitting somewhere between alternative rock and metal, with a slight Pelican-esque post-rock influence thrown in.

This influence was most evident in the fact that they would build a song around a single drum beat or bass line, gradually progressing from meek beginnings to a climactic end. Their lack of a really powerful or distinctive vocalist was a problem, perhaps due to the fact that the three other bands playing that night each had strong singers, but musically I was very impressed, especially by the frantic, acrobatic drumming.

The headliners of the night, A State of Flux, were launching the single "Surface Tension", which you can hear right now on the band's MySpace profile. It's been a good couple of years since I last saw A State of Flux live, and they have clearly matured as a band in that time. They ooze confidence in themselves and the appeal of their music, which blends heavy guitar-based modern progressive rock with the soulful, occasionally operatic vocal work of Roni Shewan, who possesses a genuinely remarkable voice.

As much as I have trouble coming up with a band to compare with Nucleus, A State of Flux are truly unique. They don't sound like anyone else in Melbourne, or anywhere else, at the moment; they span heavy metal, art rock, middle-Eastern music and big band jazz, and have a theatrical, cinematic influence on their live shows that would make other art rock bands envious. Their concerts are not gigs in the traditional sense, they are sensory experiences.

In my Q&A with guitarist Red Black he said that they focus a lot more on the recorded aspect of the band as opposed to the live aspect, but if you see them live you'd never be able to tell. They're one of Melbourne's best-kept musical secrets, but with an interstate tour coming up, they may not be exclusively ours for much longer.