Retrovision: the Test Card projected before Portishead’s performance at ATP's I’ll Be Your Mirror; a nod to Ally Pally’s past, perhaps?

Rock bands such as the Velvet Underground and Pink Floyd have used visuals in their live shows since the 1960s. But in this post-MTV internet age, even if you’re a band with a magnetic stage presence, having a huge projector behind the group (and to left and right too) now seems mandatory, even if it is just so the audience can see the band a mile away. But in recent years hip bands (who are possibly dull to watch) are projecting more than just blown up images of themselves; many are showing short, experimental films or projections.

At ATP’s I'll Be Your Mirror festival curated by Portishead in London last weekend, perhaps befitting music that was largely discordant, many of the bands had visuals that were distorted and retro: Godspeed You! Black Emperor had black and white mock film slipping and melting/burning in the projector with old-fashioned text and medieval imagery overlapping; Beak> had distorted 80s arcade games; Portishead had flickering, distorted video effects; Books used found 1980s VHS home movies. Members from Portishead and Goldfrapp provided the live score for Dreyer’s silent 1928 classic The Passion of Joan of Arc whilst Alan Moore and Stephen O’Malley collaborated for a soundtrack and narration to Harry Smith’s 1962 film Heaven and Earth Magic. In short, the music may have been post-rock but the visuals, even though they were all digitalised, were made to look pre-MTV, even pre-TV.

Presumably no accident, then, that it all took place in Ally Pally, birthplace of TV – the world’s first regular high definition service was augured there by the BBC, 2 November 1936 (says its blue plaque).

Several of the bands were instrumental – so, really, any visuals would probably work, seeing as there are no vocals to provide narration. Ever tried playing an album whilst watching TV with the sound turned down? At some point – no matter what the music or TV programme – they’ll be a moment when sound and image complement each other perfectly.