The ostinatos are more ominous. The slow chords hang in the air like wraiths. The one which sounds coolest, to my ears, is the Babylon 5 theme, which is just majestic and echoes through your mind with the thought of our last, best hope for peace. But the Doctor Who theme sounds like alien monks chanting their slow Gregorian observations — plus you can totally hear how Delia Derbyshire made one of the earliest pieces of electronic music by pasting together bits of tape by hand.

The cities of the future will be huge and super-dense — but will they also be alive? Could the increasingly complex systems needed to manage the next generation of megacities become our first true artificial intelligence?

People have speculated before about the idea that the Internet might become self-aware and turn into the first "real" A.I., but could it be more likely to happen to cities, in which humans actually live and work and navigate, generating an even more chaotic system?