El Sistema orchestras may be "transformative" and produce positive changes in the lives of young participants, but there are also negative aspects to discipline and authority that may lead to exclusion. This article positions itself within the current debate on Sistema by treating symmetrically its potentially positive and negative sides. We analyse a rehearsal session during a summer camp of a Portuguese Sistema-inspired orchestra program, focusing on the production of order, the socio-musical interactions among participants, the conductor's leadership and authority, and the young players' postures and reactions. This is taken as a case study to discuss to what extent discipline and authority, as constituents of orchestral socialization, may be empowering to participants by developing their skills or, on the contrary, symbolically violent and boring. The rehearsal was video-recorded and watched, events were categorized, selected and analysed qualitatively. The article finishes with a critical reflection on the ambivalence and contradictions of discipline and its wider implications for education.