User interfaces are hardly limited to personal computers: even by a restrictive definition, they're ubiquitous around us from ballpoint pens to stick shifts.

Here, for instance, are some user interfaces for generating music through the vibration of strings:

... and here, for turning the motion of air to a like purpose:

... and here, an interface common (to an extent) to both:

It has ever been the business of music to avail itself of new technologies. Small wonder that many such start from the familiar means to generate music, and the familiar interfaces:

But technology can also open unthought-of new channels for a person to relate to his or her creative output ... and entire new ways to create. For instance, the omnichord:

... the theremin:

... and the reacTable: