Each day is marked out with a note to keep the beat, then the deaths come, sometimes in clusters of notes, other times in rising and falling scales. 

This is the sound of the pandemic in Switzerland, as imagined by Swiss journalist Simon Huwiler. 

His composition is punched into a long roll of paper - each hole converted into a note as it is fed through an old-fashioned music box, the type with a wind-up mechanism. 

The combination of music box and paper, Huwiler told AFP, was perfect "because you see what you are going to hear". 

He had bought the music box in China and describes it as an innocent instrument used "to play little melodies to get kids to sleep". 

"When you combine this innocent instrument and the heavy data from suffering, you get this clash of emotions," he said. 

Huwiler, a data journalist for Tages-Anzeiger newspaper, says he wanted to make a visualisation that could move people and "show in an emotional way that people are dying". 

'Crowns and tears'

In the video he posted on Twitter and YouTube on Tuesday, the viewer sees the music box in close up, its handle turning constantly while the paper feeds through. 

At first, the monotonous beat simply marks the passing of days while there are no COVID -19 deaths in Switzerland. 

The title of the piece scrolls past: "A Song of Crowns and Tears, Written by COVID-19 and shu", referring to Huwiler's initials. 

Then a message appears: "First victim", and a melody emerges with each passing death, scales rising and falling, clusters of deaths sometimes forming chords.

The viewer can both hear and see the music becoming more intense as the second wave, which brought many more deaths in Switzerland than the first, takes hold. 

It builds to a climax as it hits the peak of mortality in autumn last year. 

'Huge feedback'

The holes do not perfectly correspond to the numbers of the pandemic, he says, but they reproduce the variations in a kind of artistic interpretation of the statistics. 

"On the right side of my screen I had the daily death rate, on the left side the music notations," he said. 

"Then go day by day and look what note is appropriated, what really makes sense with the data but still get some flow into the melody." 

The perforated paper strip is four metres (13 feet) long and the whole thing took him about a month to create. 

Much to his surprise, the video has attracted thousands of views online and national media have picked it up. "I did not expect such a huge feedback on this project!" he wrote on Twitter. "Thank you all!" The pandemic has killed almost 10,000 people in the Alpine country of 8.6 million.