Wired introduces the world of PMCs (polyphonic multi-dimensional controllers) as ‘revolutionary’ MIDI machines that

can sense finger movement in three dimensions simultaneously—in addition to controlling volume, a musician can also change a note’s pitch and timbre in real time.

The article details the Linnstrument; others cited include the Roli Seaboard, the Haken Continuum, the Eigenharp and Madrona Soundplane.

Fifty years from now, the 1970s to 2015 will be regarded as a strange period in history when people played musical sounds with secretarial input devices: on-off buttons, switches, sliders, and knobs. Controlling numbers by pressing keys. That’s a horrible interface. – Roger Linn

Over at Youtube you can check out what Roger had to say at NAMM 2015, and this well-played Linnstrument using a classic guitar patch.