Finely cutting food with a knife, tying a knot, driving a car. Many of the ordinary actions people perform every day require fine motor control and skilful manipulation of objects. Apparently simple mundane tasks are learnt through repeated practice and can be performed in many different ways—slowly, subtly, strongly, virtuosically fast. Similarly, playing a musical instrument involves coordination between perception and movement to perform the dynamic variations that underpin musical expression. In this collaborative project between UdK Berlin and Oxford University, we are looking at the act of pouring liquids into vessels and its underlying expressivity. We are collaborating with two professional musicians and a digital instruments designer to craft interactive sound vessels using machine learning and rapid prototyping techniques. Together with the musicians, we will examine how pouring actions can become music performance gestures.