It was one of those slightly awkward moments when no-one seems quite sure what to do. There was quiet apprehension, calm confusion, before a ripple of polite applause broke the silence. And then, the invited guests at the launch of this year’s Edinburgh Art Festival went back to their conversations and glasses of white wine.

“It’s a funny thing to have an opening around,” said Susan Philipsz, the Turner Prize-winning artist whose Timeline sound piece had momentarily wrong-footed us all. “But I guess it is appropriate really, to have something that sounds like it’s a launch, like the popping of a champagne cork or something. But it is so fleeting.”

For the duration of the festival, which runs until 2 September, Philipsz’s voice will, for a few seconds each day, punctuate the lunchtime hustle and bustle that is Edinburgh in the festival season. Immediately after the firing of the city’s famous One O’Clock Gun (every day except Sundays), the sound of the artist emulating the noise of a ship’s siren will be heard across five sites, from Nelson’s Monument on Calton Hill in the east, to outside the Scottish National Gallery – where the launch event was taking place – in the west.

“Each site is very slightly time staggered to create a domino effect,” explained Philipsz. “The siren is sung in three harmonising tones in the key of G, because I learnt that ships’ horns used to use three tones to get a fuller sound.”

The installation follows the line of a 1225 metre cable that was installed in 1861 between a master clock on Calton Hill and Edinburgh Castle. Its purpose was to ensure the timing of the gun was accurate. A map was created at the same time, showing how long it took for the sound of the gun to travel to different parts of the city.

“The sound changes all the time as it travels and I do think you get a real sense of it moving through the city,” explained Philipsz. “The thing about the speakers is that it’s almost as if the further away from them you are the louder they get. At Calton Cemetery you can hear them in the whole space, going right through the cemetery, but when you’re up close it’s not as loud – it’s strange. I think the cemetery is my favourite place to hear it.”

The Berlin-based Glasgow artist was commissioned to do Timeline over a year ago. She was working on it at the same time as producing her harrowing and moving piece for Documenta 13 in Kassel, Germany, which references the story of Jewish composer Pavel Haas, who died in Auschwitz. The Edinburgh commission was, in contrast, “celebratory” said Philipsz.

“When I was first asked I thought, ‘It’s the same year that I’m doing Documenta, can I do it?’ But I so wanted to be part of the festival because I think it’s doing a really interesting programme. So, I just made it happen.”

Timeline continues at five sites across Edinburgh at 1pm daily (except Sundays) until 2 September 2012. More information at

Read Richard Taylor’s preview of the Edinburgh Art Festival here