An "Instrumentalist" is someone who believes that the value of a theory or concept lies in its practical applications and usefulness, rather than in its ability to describe reality accurately. This perspective is often applied in fields like philosophy, science, and music, where the focus is on how theories can be used as tools to achieve specific goals. In music, an instrumentalist refers to a musician who plays a musical instrument, as opposed to a vocalist. These musicians can perform in various genres, showcasing their skills through solos or as part of an ensemble, contributing to the overall sound and experience of a performance.