A multi-touch capacitive touch control strip

Another possibility for those exploring alternate controllers

The Trill capacitive touch strip](Trill touch sensors ), with 30 steps (interpolation should net finer resolution), photo shows multi touch output signal.

Available from pimoroni for £15 (strip an d interface board)

Trill Flex demo brief

Sales Video

Hacker Video on their rigid Trill input device.

( is apparently not open source)

A couple of example projects from their blog, using other Bela sensor products.
Trill Guitar Project

Kalichord Strum - An instrument that offers nuanced rhythmic strumming