The Chems will have a one-off lights-sounds-images show from United Visual Artists and Flat Nose George, which will make the evening all the more special.

So, we hear you cry, where can you get tickets from? Well, most went several months ago (completely passing us by), however the ICA (with whom the event is in partnership) have got a few left. All you need to do is answer the below question:

Which band did United Visual Artists collaborate with in 2003 to present stunning digital representations of realtime information about the world?

Email the answer to This e-mail address is being protected from spam bots, you need JavaScript enabled to view it with the subject line 'Chemical Brothers Trafalgar Square'. Entries must be received by 12 noon on Wednesday 5 September, and winners will be informed by email by 12 noon on Thursday 6 September.