In this paper, we introduce the concept of VR Open Scores: aleatoric score-based virtual scenarios where an aleatoric score is embedded in a virtual environment. This idea builds upon the notion of graphic scores and composed instrument, and apply them in a new context. Our proposal also explores possible parallels between open meaning in interaction design, and aleatoric score, conceptualized as Open Work by the Italian philosopher Umberto Eco. Our approach has two aims. The first aim is to create an environment where users can immerse themselves in the visual elements of a score while listening to the corresponding music. The second aim is to facilitate users to develop a personal relationship with both the system and the score. To achieve those aims, as a practical implementation of our proposed concept, we developed two immersive scenarios: a 360º video and an interactive space. We conclude presenting how our design aims were accomplished in the two scenarios, and describing positive and negative elements of our implementations.