Abstract : We examine quality issues raised by the development of XML-based Digital Score Libraries. Based on the authors' practical experience, the paper exposes the quality shortcomings inherent to the complexity of music encoding, and the
lack of support from state-of-the-art formats. We also identify the various facets of the ``quality'' concept with respect to usages and motivations. We finally propose a general methodology to introduce quality management as a first-level concern in the management of score collections, and an initial taxonomy of quality problems based on real use cases.