In recent years, immersive technologies such as augmented and virtual reality have gained significant popularity and found applications across various research domains. This paper focuses on the adoption of such technologies for musical purposes, particularly in enhancing accessibility in musical performance. In the domain of Digital Musical Instruments, extensive efforts have been made to develop accessible designs and interfaces for music creation. Concerning Virtual Reality Musical Instruments (VRMIs), one notable challenge is the discomfort stemming from using controllers to interact with objects in the virtual world, specifically for people with a physical disability. In fact, the design of these applications often incorporates objects that require precise control. The proposed solution is an accessible VRMI, called Sound Blocks VR, which accommodates both controller-based and hand-tracking interactions to address the needs of individuals with physical disabilities (especially motor-impaired users) or, in general, who feel uncomfortable using controllers. Where available, the passthrough feature can also be exploited. The usability of Sound Blocks VR was evaluated using the System Usability Scale through interviews with musicians and nonmusicians. The average usability score computed on 17 participants is 87.94 out of 100, which indicates that participants found the experience intuitive and user-friendly. Moreover, some qualitative questions were posed to investigate specific aspects of the experience design.