This presentation is part of a wider research project that analyses the benefits of collective musical programs in the post-traumatic recovering of people who experienced violence because of the armed conflict in Colombia. Sound postcards, a research methodology derived from socio-acoustics, contributed to ethnographical research with participants in the Music for Reconciliation Program of the Batuta Foundation in Colombia, and allowed researchers to identify the changes in the density of their social fabric, before and after being victims of the armed conflict. The paper discusses the extent sound postcards enabled to recognize the importance participants attributed to joining in the music program in a number of areas, including recovering social cohesion and personal identity. A more detailed discussion of the use of sound postcards can be found in a recent article by the co-authors in British Journal of Music Education (Rodríguez-Sánchez, Odena & Cabedo-Mas, 2018)