Andrew McPherson

Researcher, composer, engineer and instrument designer


Multi-touch sensing on the piano keyboard

TouchKeys is an augmented instrument using capacitive touch sensing to transform the keyboard into an expressive multi-touch control surface. The TouchKeys sensors can be added to the surface of any keyboard, using capacitive touch sensing to measure the location of the musician’s fingers on the keys during performance.

Following a successful Kickstarter campaign in 2013, TouchKeys spun out into a company, TouchKeys Instruments Ltd, which sells kits and instruments to musicians.


More information on the research behind TouchKeys can be found on the Augmented Instruments Lab TouchKeys page. The formative research took place in two phases:

  1. Capacitive sensor design. I tested many configurations and geometries of capacitive sensing to find an approach that allowed fast, accurate sensing on circuit boards shaped to fit each key of the piano keyboard.
  2. Studying keyboard technique. Playing the piano is already a highly complex task, and any augmentation must be compatible with the years of practice that pianists spend to develop their technique. I analysed pianists’ technique to discover how to distinguish intentional movements on the key surfaces from unintentional byproducts of traditional playing.

Musical Applications

TouchKeys allows the player to flexibly assign different movements to different control parameters of their synthesisers. Example techniques include:

  • Shaking the finger side-to-side to perform a vibrato
  • Sliding the finger up and down to bend the pitch
  • Sliding the finger to control filters and other effects
  • Touching the key with a second finger to rapidly restrike a note
  • Splitting the keys into multiple regions for microtonal performance
  • Emulating nuances of string and wind instruments with subtle movements

Examples of these techniques can be found on my YouTube channel.