The Robertson String Orchestra (RSO), established in late 2024, is a string ensemble for advancing students at AMEB Grade 5 level or equivalent. The orchestra focuses on developing rhythm, intonation, sight-reading, orchestral etiquette, and advanced musical understanding through challenging and engaging repertoire.

RSO rehearses weekly on Wednesday evenings during school term and presents concerts in a professional performance venue. Managed by Heidelberg Orchestras Inc, the orchestra operates as a non-profit ensemble with audition and membership requirements, and places strong emphasis on commitment, collaboration, and high standards of participation.