Children and adults scavenge for food and recyclable materials among mountains of stinking junk under an unbearable sun.
Sonidos de la Tierra now has 8,000 students in 120 communities
Suddenly the sound of violins playing Handel's Music for the Royal Fireworks breaks the sound of stray dogs' barking and rubbish trucks, taking the visitor to the streets of any European city like Prague or Vienna.
This is Cateura, the main rubbish dump of Paraguay's capital, Asuncion, where the conductor of the country's symphony orchestra, Luis Szaran, has established a music school.
"I came here once and saw a woman holding a newborn child with one hand and picking up rubbish with the other, and told myself this could not go on, this is how everything started," recalls Mr Szaran, who is of Hungarian and Polish origin.
He launched the Sonidos de la Tierra (Sounds of the Land) initiative six years ago to bring classical and folkloric music to the poorest children with the help of the Swiss non-governmental organisation, Avina.
The programme now includes 8,000 students in 120 communities throughout Paraguay, one third of whose 6.5 million population lives on less than $2 (£1) a day.
Music has changed my life - I feel completely different
Israel Sonidos de la Tierra student
"Music has changed my life - I feel completely different," says 11-year-old Israel, one of 65 children studying at Cateura, while holding a violin tightly with his hands.
"Before I used to feel depressed all the time, but now I have hope," adds Maria del Carmen, 19, sitting in front of the teacher who is also charged with checking that they do well in school.
On the other side of the classroom door, their parents busily sort out recyclable materials from rubbish which they later sell back to industries for a meagre profit.
A group of Cateura students this year played at Oxford University, where Mr Szaran received a social entrepreneurship prize three years ago that has allowed him to continue expanding his ambitious project.
Nearly all of the scheme's resources are generated by the communities
The most gifted children are now able to pursue a music career with the help of grants from European families and even be taught by members of prestigious orchestras like the first violinist of the Berlin Philharmonic.
Were it not for Sonidos de la Tierra, they would be left to roam the dirt roads all day, rummaging through rubbish without their parents knowing their whereabouts and moving to work in the actual rubbish dump at the age of 11.
There are few other choices for this community of 10,000 people which directly depends on rubbish for its existence.
Cateura is a miserable place where the police do not dare enter at night, and where illnesses and epidemics are widespread due to the lack of clean running water.
But the children in the programme are not only taught to play music. They also learn how to build and repair musical instruments in an adjacent wooden workshop.
They are granted credits to buy materials like strings and other specialised music components for their instruments. When they have sold or repaired an instrument they can earn money that allows them to make a living and maintain their studies.
Recently, they have even started building high-quality instruments made of rubbish.
Alberto, 20, shows me a drum which incorporates an X-ray of a spine, while his teacher tunes a guitar made of sweet potato cans that was used at Oxford.
"After joining the programme, I returned to school to finish my studies. My dream is to become a luthier (someone who makes or repairs stringed instruments)," he says while fixing a trumpet, an unbelievable sight considering that eights months ago he worked at the dump.
Unlike other social music initiatives - such as the one in Venezuela whose orchestra played at last year's BBC Proms in London - Sonidos de la Tierra does not depend on external donors.
Ours is a broken society where pessimism is the norm, but until change comes we'll continue trying to save children
Luis Szaran Founder, Sonidos de la Tierra
More than 90% of its annual resources - $10m (£5m) - is generated by the communities themselves.
"When arriving at a new place, we donate the instruments and provide a teacher," says Mr Szaran. "Then we form an association of adults and teach them management and accounting."
"When ready they go and search for funding, sometimes building their children's music school with their own hands."
In fact, he explains, the overall purpose is to create a culture of accountability and respect, especially towards women and children, and provide skills for people so they have a chance of escaping their miserable existence in the absence of any meaningful assistance from the government.
But Mr Szaran admits that this success story cannot hide the overall desperate situation in Paraguay, one of the most corrupt countries in the world.
He believes that former Catholic Bishop Fernando Lugo, who won the presidential election in April and happens to be a former guitar student of his, represents the only hope.
"Lugo is different to everything we've seen before, this is a country held with pins at the mercy of a corrupt elite," he says.
"Ours is a broken society where pessimism is the norm, but until change comes we'll continue trying to save children."
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