Digital music production processes trace a great amount of processes and objects. The important flow of these traces calls for a system to support their interpretation. We have studied and developed such a system in the digital music production context -within the Gamelan research project -towards musical object and process reconstitution. We present the results we obtained from combining trace engineering, knowledge modeling and knowledge engineering, based on the differential elaboration of a strongly-committed ontology, standard formats and common knowledge management tools. We conclude by discussing some hypotheses about trace-based knowledge management, digital music preservation and reconstitution, opening on to some considerations about artistic style and digital humanities aspects.