Capturing the personnel needed to perform a musical work in MEI metadata is straightforward with standard ensemble configurations, such as string quartets. In contrast, it can be highly complex for extensive orchestral settings, stage music, or, e.g., twentieth-century ‘Neue Musik.’ Especially in the latter case, the degree of possible variation is virtually limitless. While MEI 4.0.1 offers places within (descendants of , ) for capturing such data and provides means for quite complicated data structures through, e.g., nesting or referencing, there is still room for improvement. First of all, data structures should stay as simple and generic as possible. That is to say, that structural modification and a more detailed description of MEI’s data model for the benefit of a more concise encoding should be the target, especially when envisioning a more structured encoding of more complex setups. For example, representing dependencies between performers and instruments is extremely limited in the data model for in MEI 4.0.1 (see definition of and also Gubsch & Ried, 2021). This poster takes as a starting point issues from two edition projects dealing with music from the twentieth century to illustrate philological intricacies and investigate the possibilities to encode them with MEI 4.0.1.