Our behavioral characterization of musical WM (Study 1) has unveiled the superiority of adult musicians in the maintenance and manipulation of musical stimuli. Expert musicians are characterized by long-term deliberate musical practice (Ericsson, 2015; Ward et al., 2007).

Longitudinal and cross-sectional experiments with children aged 6, 8, 10, 12, 14, and 16 years aim to unveil the development of musical WM. We are particularly interested in answering the following questions:

• Does musical WM develop linearly, or what are its developmental stages, and how are they characterized?
• Can we disentangle maturation from training effects? What is the correspondence between musical training and age to match the WM abilities of adult non-musicians?
• How do WM transfer effects emerge and develop with age and musical training?

Healthy children undertaking formal musical training constitute the musician groups, and children undertaking other activities constitute the non-musician group. Children in both groups perform a gamified version of the maintenance and manipulation CAT tasks developed and validated in Study 1. In the story plot, the child helps fix musician robots affected by an electric storm. The gamified paradigm is developed in PsyNet and is designed as an open-source, customizable research tool. In addition, we administer short questionnaires about demographics, general intelligence (e.g., Wechsler Intelligence Scale for Children, WISC-V Test; Kaufman et al., 2015), musical experience (an abridged version of the Goldsmiths Musical Sophistication Index for children; Buren et al., 2025) and musical ability (e.g., Montreal Battery of Evaluation of Musical Abilities, MBEMA; Peretz et al., 2013). The study involves close collaboration with music schools, regular schools, and high schools in the Frankfurt area.