De-selection is rarely an option for music literature except when warranted by the material’s condition. All materials have value as reflections of the scholarship of the times, even if superseded or contradicted by newer materials.
Unique copies being de-selected due to condition will be replaced if at all possible. The preferred replacement of a paper copy is with another paper copy; however, this is subject to availability. Format is less important than continuing to retain content; preservation photocopying may be considered.
Journal articles should be replaced when possible with photocopied pages if the paper copy needs to be kept. Many journals are now available in good digital copies, which may allow some withdrawal of paper volumes, subject to moving walls and other criteria. Subscriptions to both paper and online versions of the same title will generally be dropped in favor of online where available and if reproduction of illustrations, musical examples, etc., is of sufficient quality.