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Undertow

Commissioned by the City of Melbourne and Knowledge Week, this data-driven musical installation at the Federation Bells used city data on Melbourne’s water to inform its melodies.

The land where Birrarung Marr Park and the Federation Bells now stand were underwater: forming part of a system of rivers, creeks, marshland and lagoons, much of which today has been driven underground and away from the city’s conscious face. Now contained in a network of drains, some trace an underground path mirroring – or mocking – the rivers’ original flow. Using the City of Melbourne’s Open Data Platform, Bridget Chappell combines contemporary and historical data of local water management and water colonisation. Through a process of sonification – the musical representation of visual data – she performs an original work: an aural painting of the last 185 years of the Birrarung River (“Yarra”) and Narrm bay (“Port Phillip”) composed for the Federation Bells, cello, and samples, presented as an installation throughout Knowledge Week and performed live on location on 23 May, at the Federation Bells, Birrarung Marr. The proceeds of this work will go to FIRE organisation’s campaign delivering water to drought-stricken communities in Gamilaraay country (NSW), and Warriors of the Aboriginal Resistance.

Forthcoming is the vinyl release of Undertow through the City of Melbourne.

Artist’s statement

When I received this commission, I was immediately drawn to three data sets in the Open Data portal: three maps all relating to what you could call the City’s water management. Two colonial maps from the 1830s showing a rendition of the original flow of the Birrarung River – today known as the Yarra, and all the swamps, wetlands, and billabongs surrounding it, and creeks the flowed into it. The other was a contemporary map of the City’s underground drain network. I knew that the river had been manipulated and reshaped somewhat by settlers, but I didn’t know the extent of it. This data drove me to research the colonial history of the river up til now, and its the collation of this research that has informed the work.

The idea of data sonification is to make visual data – like a map or a graph – audible. So it holds a lot of potential for accessibility, such as for people with vision impairments. But it’s not a new idea. One of the best examples of data sonification we have is one that’s been practiced on this continent for thousands of years – the Indigenous use of songlines, or a musical method of both navigation over vast distances, and reflection on the creation histories of the landscape. My method of sonification is nowhere near as sophisticated. Nor is it my place as a settler to try and sonify the landscape, as though it could be objectively represented by me. The idea of data is a loaded one. Things like maps, which are easy to mistake for some kind of neutral representation, have played powerful roles in colonisation and gentrification. The idea of “data” prioritises certain kinds of information over others, and downplays the emotional ways we convey and digest information. So I set out to develop a process of sonification as a compositional tool, for discussing histories of the Birrarung River that are not talked about very much. They are all things that have been done to the River since European settlers began colonising it.

The piece is divided into four movements, each using a different combination of data sets. The first movement is about the wetland that was right here where we are, in Birrarung Marr. It was filled in along with other billabongs and marshlands on this part of the river in the 1890s. The second movement is about the dramatic re-routing of the western rim of the river before it flows into Narrm Bay. The river used to flow north of what is now North Melbourne, through Kensington, and converge with the Maribyrnong. This was changed drastically at the turn of the 20th century, with parts of the river filled in, billabongs buried, and other land created out of the sea like Coode Island. The third movement is about the destruction of Yarra Falls in 1883. This small waterfall was where Queens Bridge now sits in the city, and was a natural demarcation between the fresh water upstream and the salt water coming out into the Bay downstream. The rock wall prevented boats from traveling further upstream, and was also a main flood point. Dynamite was used to destroy the waterfall The final movement is about the river that ran down the middle of the catchment, which is exactly where Elizabeth Street sits now. Water rolls down into the valley where this road now runs, the river driven underground into a huge drain that mirrors, or mocks the original body of water. When comparing the historical and contemporary data available on the river – the maps of the original water ways, and the modern map of the drain network – you can see that the original waterways are all still here, despite colonisation. Elizabeth St is still in the middle of a valley, and despite colonial attempts to re-route the water, you can’t re-route a catchment the size of 150 football fields. Elizabeth St often still floods, reminding us of the river that flows under the road. Listen for floods throughout the piece; but especially in the final movement.

Overall, the Bells play the part of the water itself. Their melodies stem directly from sequences written by data sets – asigning MIDI notes to geospatial data of particular bodies of water. They play what in baroque music is called a basso continuo – a repetitive melody that plays throughout, forming the backbone of a piece. It’s traditionally what the 16th century ancestor of the cello played, so it was a nerdy private joke with myself to make the bells play this instead. It’s also a way of expressing the permanency of the river, despite colonialism.

The pitch of the Bells follows the latitude (or north-south axis) of its flow. Because water in the catchment generally flows north-south, you’ll hear quite a few descending melodies. But when expressing a 2D object on a map – like a wetland – the melody moves from west to east along the body’s longitudinal axis, and I have used an arpeggiator to move between the northern and southernmost points of the object.

The cello carries several different roles – to do with different aspects of the river – its speed of flow, seasonal flooding, and other factors. There are a few types of sounds you can listen out for as story-telling devices. When I play long, deep, sort of uncomfortable sounding noises, it’s telling you about the dredging of the river – to widen and deepen its course to allow bigger boats to pass through it. When I play a series of rising notes, it’s telling you about parts of the river flooding.

The role of percussion and drum beats represents the colonial industrialisation of the river. The use of dynamite to destroy Yarra Falls hasn’t been dressed up – you’ll know it when you hear it.

Water flow attenuation has been indicated by gating notes. Water driven underground is expressed through reverb, indicating a change in its environment, or filters on the notes.

The city’s detachment from the river – not exactly data, but I wanted to consider it – is expressed through glitch. This has been used sparingly rather than throughout – you can listen out for the vapor wave motif – otherwise known as the sound of capitalism.