This document deals with data quality in Digital Libraries of Scores (DSL). Data quality management means assessing and possibly improving quality of data. It is a major concern of the information system lifecycle. The first and fundamental step of the data quality management process consists in eliciting data quality requirements. Because data quality is defined as being the fitness for use of data (meaning that the notion of data quality depends on the context), it is a conceptually complex notion, whose implementation for a given use case is not trivial. So context-dependant guidelines are needed in order to help users to define data quality in their context. This is the problem that we tackle here, by proposing a set of quality rules specific to DSL, which can serve as a basis in order to elaborate users' quality requirements.