In this paper, we describe the prototyping of two musical interfaces that use the LeapMotion camera in conjunction with two different touch surfaces: a Wacom tablet and a transparent PVC sheet. In the Wacom use case, the camera is between the hand and the surface. In the PVC use case, the camera is under the transparent sheet and tracks the hand through it. The aim of this research is to explore hovering motion surrounding the touch interaction on the surface and include properties of such motion in the musical interaction. We present our unifying software, called AirPiano, that discretises the 3D space into 'keys' and proposes several mapping strategies with the available dimensions. These control dimensions are mapped onto a modified HandSketch sound engine that achieves multitimbral pitch-synchronous point cloud granulation.