The loudest field still needs water

Sofia likes a festival field before it fills. It is all invisible decisions then: where the sound will land, where the queue will bend, where the first tired person will look for water and whether the gate can welcome excitement without turning it into a crush.

"A loud evening is still made from quiet details," she writes. "The cup, the bottle rule and the opening time are part of the score."

Two evenings, one hot field

The City presents City Sounds as two open-air concert evenings at Champ du Glacis for National Day, with DJs, international performers and local acts. The first night, 22 June, opened the gates at 17:00 and began performances at 20:30, with an electronic-music programme. The second night, 23 June, opens at 16:00, then moves through OKE, TALI, CLOCKCLOCK and ONEREPUBLIC.

Those names make the poster. The heat warning makes the evening usable. Because of the heat wave, free drinking water is available at all catering stands, served in refundable deposit cups or in personal plastic containers. Visitors may also bring one unopened 0.5-litre PET bottle of water per person.

• A gate time is crowd design.
• A water cup is safety equipment.
• A bottle rule can be hospitality if it is clear before people arrive.

Care has to be loud enough

Sofia does not want the practical information to whisper from the bottom of the page. In hot weather, the care instructions have to be as visible as the stage times. People remember the chorus; their bodies remember the queue, the sun, the refill and the walk out.

The City also points visitors toward bus access around Hamilius. That detail matters after midnight, when a crowd becomes a set of smaller decisions: stay, leave, wait, refill, find friends, find the stop.

The concert is a temporary city

By the time the last set is scheduled, Champ du Glacis is not only a venue. It is a temporary city with weather, rules, routes and public services. Sofia thinks that is why a festival can teach urban design so quickly: every weak point becomes visible before the encore.

The best version of City Sounds will be remembered for sound. The kinder version will also be remembered because nobody had to choose between music and water.