It can be difficult to navigate the tasks of repertoire selection and part assignments in a way that produces a successful performance product while also being educationally beneficial to all students. However, researchers have explored methods of ensuring these goals through repertoire selection. In this article, I present ideas for how educators can pair the Zone of Proximal Development (ZPD) with music aptitudes when assigning parts in an ensemble. In doing so, ensemble directors might find themselves better positioned to address the individual needs of every student in the ensemble.