We missed the marvellously named Feed The Rhino, but we did get there in time for The Defiled, and I was left a little confused. Their image is straight out of the Kerrang metalcore styling manual, all crazy hair and grubby-looking (but likely relatively expensive) outfits, and their music is admittedly pretty punishing. Ok, so the constant double-kick-drums get really quite tiring after, oh, two songs, but the electronic effects that burble underneath, and frequently turn into phenomenal, sub-bass shocks, make them stand out a bit at least. Saying that, though, their songs were so one-dimensional, at least to my ears.

I can thank them for one thing, though – to remind me to dig out The War of Art by the much-missed American Head Charge. A band who were doing something similar, but with less cliches, much more impressive sonic variety, rather more danger and a whole truckload of awesome songs.

Far more interesting were the two, kinda co-headlining bands, both of whom I had a big interest in seeing. Perhaps a little surprisingly – they've been around quite a while longer, for a start – Gojira were on first, but wasted no time with their set and indeed started a few minutes earlier than billed, that clearly allowed them to squeeze in another song within their set.

That time was well spent, too, a blistering fifty minutes of ultra-technical metal that is, perhaps, surprisingly melodic at times too. There were too many highlights to pick, but those songs I've waited longest to hear live – i.e. those from their breakthrough album From Mars to Sirius, as somehow I've never seen these guys live before – were all an utter joy. But the most joy for me was to be had from the moment the hulking great riff that heralded the arrival of Flying Whales was unleashed, as the second song. No song that crushing should be that catchy – and shorn of the lengthy intro that the album version has, it had an even more crushing impact.

Crushing is a word that could be used for much of their music. In technical terms they are in similar realms to Meshuggah and Mastodon, but with a melodic and environmental sensibility that stands them out as almost entirely unique band. How many other metal bands write about environmental issues, about conservation, without being laughed at? That they don't here is perhaps down to the sheer conviction in everything they do.

By the time newer track The Gift of Guilt closed things with a flourish of freefalling, heavy-as-a-heavy-thing riffs, I was hankering for more of this band's glorious meshing of technical ability and accessibility. Judging on the crowd's roar as they left the stage, I wasn't the only one.

We weren't disappointed for long, mind, as following them were GHOST, a Swedish band who've made quite a splash in the few years they've been around. It has to be said that this isn't just for their music – impressive enough, mind – but perhaps more for their unusual nature. Like, their choice of total anonymity, and their striking onstage appearance.

Not for GHOST the regulation metal band appearance. Most of the band are literally cloaked in black, even with black masks and hoods covering most of their faces – the five of them being known as "the Faceless Ghouls", while the lead singer is a demonic, mainly-black clad "Bishop" or papal character, by the name of Papa Emeritus II (the first "handed over" to the second at a show in Sweden at the turn of the year).

His entrance to the stage was an object lesson in stagecraft, too. While the rest of the band trooped on during the intro, and cranked up the music, Papa Emeritus II remained out of sight. That is, until enough dry ice had filled the stage to shame the Sisters of Mercy, and as his moment came to add vocals for the first time, the smoke suddenly cleared and he simply appeared, mid-stage. It was fucking epic, frankly, and the band's music on-stage matched exactly that.

My one complaint, perhaps, of their recorded material up to now – particularly on debut Opus Eponymous, was that it was maybe a little thin, lacking in bite or heaviosity. No such problem live, with every single song a hell of a lot heavier, and it made a few so-so album tracks into utter monsters live. The heavy, doomy basslines of Con Clavi Con Dio thundered through the room, the closing Ritual sounded less a seventies-tastic monster mash and more an enthralling satanic embrace, while Elizabeth shook off the KISS-esque sounding bassline and instead was evil-hearted nastiness – as any song about the evils that Countess Báthory was reputed to have done should be. On another note, how many sodding songs about her do I now own? I can think of at least four off the top of my head, and it would appear I actually have a few more…

The new material absolutely slayed, too. Opener Per Aspera ad Inferi was a fantastic, almost-psychedelic occult-rock track, complete with a chorus entirely in latin (and does that title really translate as "rough as hell"?!), while first single Secular Haze has carny-esque keyboards, and a rolling rhythm that sounds almost Opeth-like until Papa Emeritus enters the fray.

The thing is, though, is that taking each element of this band really doesn't do them justice. At their core, they are a seventies-and-psychedelic rock influenced band, but their overt Satanic lyrics and imagery, and of course the extraordinary, striking image and live show, make them a band that really do rise above the sum of their parts. Like many others, I'm not actually bothered who is behind the masks – it would break the spell, somewhat.

In the meantime, they are a band absolutely worth seeing – and it will be interesting to see whether the forthcoming album Infestissumam can do more justice to their live sound. Here's hoping.