One of the knock-on effects of all the advances in computer technology is that some remarkable little black boxes are now available. They make it possible for the tiniest of movements to have a big musical effect. Here are just some of them.

• Soundbeam uses an invisible sonic beam to give anyone control of electronic instruments.
• MIDIcreator does the same with a bit less sophistication but offers a vast additional array of switches. You can now play a 64 bar guitar solo simply by shifting your weight on a cushion.
• Apollo Ensemble is similar to MIDIcreator but links in with your computer to give as simple or complex a range of possibilities as you like.
• There are microphones that, rather than relaying sound itself use sound as a trigger for all sorts of other things to happen.