Ability grouping, or dividing students from a large band, choir, or orchestra program into smaller ensembles each with like musical ability, has been a common practice among teachers of large ensemble music classes in middle and high schools in the United States (Allsup, 2012; Glossenger & Cowell, 2021; Holsberg, 2009; Parker, 2015). Large ensemble music classes have been the most prevalent opportunity for in-school, advanced musical learning experiences among these students (Elpus & Abril, 2019, 2024). Despite the prevalence of this practice within these ensembles, little critical or empirical examination of ability grouping has occurred by music education researchers (Glossenger & Cowell, 2021; Parker, 2015). In general education contexts, the practice of ability grouping has been extensively questioned (e.g., Alam & Mohanty, 2023; Blanco-Varela et al., 2024; Catsambis et al., 2021; Fuligni et al., 1995; Gaspard et al., 2018; Henry, 2015; Kulik & Kulik, 1982; Steenbergen-Hu et al., 2016). From an achievement standpoint, researchers have found the practice of ability grouping had a slightly positive relationship with achievement, but not at a level that achieves statistical significance (Kulik & Kulik, 1982). In addition to achievement questions, researchers examining ability grouping have expressed concerns about socio-cultural conditions such as race and socio-economic status (Henry, 2015) as well as the emotional well-being of students (Wan et al., 2024). The practice was ineffective for students in between-class ability grouping conditions (Steenbergen-Hu et al., 2016). Music teachers who employed an ability grouping teaching strategy in their large ensembles have grouped students of several grade levels in one class, employing the between-class ability grouping technique. In this study, the researcher sought to determine whether the use of the practice of ability grouping was related to students' self-reported motivation to persist in their high school large ensemble music classes. Using Eccles and Wigfield's (2020) Situated Expectancy-Value Theory as a framework, motivation to persist was examined using the factors of expectancy for success and subjective task value. Students completed online questionnaires, and models of the motivation to persist using the above factors for students in an ability grouping condition and those whose teachers did not use ability grouping were constructed. Models were used to compare the groups and draw conclusions about the phenomenon of ability grouping found in high school music programs in the United States.