When you see Vienna Ditto you want to spend the whole evening – possibly the rest of your life – gazing at the sultry Hatty Taylor.

But in the end, you can’t take your eyes off the uncertified madman Nigel Firth. He staggers around the stage, wild-eyed and unkempt, crudely walloping his wrong-shaped guitar, laughing and roaring.

Do you remember Dwight Frye in the old Dracula movie, when he finally slips into insanity? Nigel Firth is like that. He’s madder than a box of cheese at a hatter’s frog convention.

Vienna Ditto are a band. A duo, technically. Their gigs involve some back projection. They were topping the bill at the O2 Academy, with Decovo, The Aureate Act and Kid Kin. I caught a bit of Decovo and they were a lot of fun. Good, punkish indie. Good singer, in particular.

It’s less easy to describe what Vienna Ditto do. They call it ‘voodoo sci-fi blues’, but I’m not sure I agree. It’s drum and bass-ish electronica, mixed with torch singing and psychedelic rock-shaped Delta blues. Plus rockabilly and folk here and there.

Hatty somehow makes her gentle, English voice sound raunchy and rather strange, in a captivating way. Every now and then she turns into Dik Mik from Hawkwind, dragging unearthly sounds from one of Nigel’s magic boxes.

Nigel bangs the boxes and gets massive, groovy beats out of them. Then, once they’re looping and booming, he’s off with that guitar. He sprays echoing, sliding notes all over the place while the sound builds and builds to a wailing, shimmering roar.

It’s fantastic, especially with brilliantly synchronised movie clips on the back projection.

Vienna Ditto are on the edge of success. Which is right, really, because they’re on the edge of everything else too. Keep your eyes on them, if you dare.