We present the Pin&Play&Perform system: an interface in the form of a tablet on which a number of physical controls can be added, removed and arranged on the fly. These controls can easily be mapped to existing music sofware using the MIDI protocol. The interface provides a mechanism for direct manipulation of application parameters and events through a set of familiar controls, while also encouraging a high degree of customisation through the ability to arrange, rearrange and annotate the spatial layout of the interface components on the surface of the tablet.The paper describes how we have realized this concept using the Pin&Play technology. As an application example, we describe our experiences in using our interface in conjunction with Propellerheads' Reason, a popular piece of music synthesis software.