Last modified on Fri 12 Mar 2021 07.08 EST On a central reservation in Puerto Madero, Buenos Aires’ youngest and least atmospheric neighbourhood, stands a strange-looking monument. It’s a twisted, abstract sculpture, in steel, that looks at first glance like the cooling fins from a motorbike engine. It is, in fact, an unfurled bandoneón (button accordion), the fiendishly difficult instrument of German origin that produces the unmistakeable sound of tango: a pained and plangent breath from a broken heart. A sculpture of the bandoneón (an accordion), used by Astor Piazzolla to produce the sound of tango , in Puerto Madero. Photograph: Cavan Images/Alamy