Lawrence Casserley (B.1941) has spent his career working on the performance of real-time electroacoustic music and the processing of other musicians' sounds, collaborating with musicians, poets and visual artists alongside solo work. He has been working to create his “Signal Processing Instrument” since the mid 1990s. The original version, created in MaxFST on the IRCAM Signal Processing Workstation, was completed during a residency at STEIM in 1997. Since 1999 it has been built in Max/MSP and used multiple different physical controllers to create an ever evolving hybrid instrument. The current (2016) version couples the software with a pair of iPads running TouchOSC and a Novation Launchpad.