The present paper investigates multilingual practices in orchestra rehearsals, where conductors and musicians collaboratively develop musical performances. The rehearsals, which bring together participants with diverse linguistic and cultural backgrounds, involve the alternation of conductors’ instructions and musicians’ implementations. For instructing, conductors use various languages from their repertoires, depending on the orchestra’s working language and geographical location, their personal preferences and competences as well as on specific interaction formats. This study examines how conductors navigate multilingualism and language choice factors and how they incorporate vocal resources like singing and embodied resources like gestures, gaze and facial expressions in achieving interactional goals. Using video recordings from Belgian and French orchestras and the theoretical framework of Multimodal Conversation Analysis, the analysis shows that conductors frequently switch between languages and other codes to ensure smooth and efficient communication. The aim of the study is to contribute to discussions on managing multilingual and complex interaction scenarios in rehearsals and in comparable (musical and other) professional settings.