With the ongoing development of virtual reality (VR) systems, such as the HTC Vive and Oculus Rift, there is a need to develop new interfaces that maximize immersion in VR. Several VR interfaces have been successfully developed and implemented for a mixed reality (MR) MIDI keyboard. MR exists along a continuum between a pure real environment and a pure virtual environment. This paper presents a collection of virtual interfaces used to augment a MIDI keyboard synchronized in physical and...