In Oscines, males sing for reproduction and defence of their territory, giving information about their species, group and individual identity and about their physiological state. It has also been shown that these territorial songs can show microgeographic variations leading to microdialects. We work on the European wren Troglodytes troglodytes, a common small passerine, singing a loud 30-40 syllable territorial song from February to June. Several males can establish contiguous territories and can interact among each other as a group of neighbours. We show that each male can sing several song types, most of which are shared with some of its neighbours. On the contrary, we have not observed any song sharing between groups of birds being separated by only few kilometres. We have two levels of analysis. 1) an intra-group analysis: what is the dynamic of acoustic communication in the network of neighbours? Who sings first? After whom? Which song types are sung? Etc... 2) an inter-group analysis: what differs in the songs of one group compared to another? Can the birds make the difference between a song of its group versus a song never heard before? We will also show results comparing the songs between the beginning and the end of the breeding season, in order to better understand the ontogeny of microdialects in those well-separated communities of forest birds.