A group of musicians from Paraguay belted out familiar tunes at a hilltop concert just outside Bolivia's capital city, overlooking a sprawling garbage dump. La Paz produces some 670 tons of trash each day, and local officials minimize the environmental impact of garbage dumps. The young musicians of Paraguay's Cateura orchestra transform trash into music, using recycled materials to make their own instruments. Local garbage workers were impressed by cellos, violins and horns fashioned out of large cans, pipes and other discarded materials. "It has the same sound as a cello made out of wood," musician Bianca Pintos said of her hand-made cello. "There's really not much difference except that this one is made of trash." The orchestra has performed in more than 50 countries.