Reading Bruce Chatwin's The Songlines, the Australian landscape appears, in the Dreamtime, like a musical score in which the lines of different songs make up a cartography of simultaneity. After centuries of sedentary lifestyle, 20th Century man lends his ear to his sonic city. From the futurist Luigi Russolo to Murray Schafer, we could draw an arc which would demonstrate the tension of sedentary man's listening. During the first half of the 20th Century, man opens his ears to the sounds of the city builds instruments which reproduce the sounds that machines produce. Later, when the hum of the streets is unbearable to him, then his ears will attune to the pressure of the sound and to his ecological and aesthetic analysis. In consequence, a sonic cartography becomes a map which attends to the distribution of a simultaneity of lines which are difficult to reconcile; demonstrating the formation of geographical-sonic strata which correspond to different kinds of classes and cultures. Sonic cartographies are ultimately a guide as to the place where each listener resides in this territory and the way in which he aims to interact with it. Each sonic cartography of a city reveals a multiplicity of cities to the ear. In a sonic cartography the ear recovers its nomadism because the sound is subjected to constant change. Along with sonic/acoustic ecology we would also have to consider what Guattari calls 'mental ecology'. This mental ecology could permit the intoning of the city we want to create and listen to