Playing in Real Time?

What is meant by real time? Is there time that is not real? While computers work incredibly fast, they nonetheless require some time to get a result. When you move a computer's mouse, you see an arrow that moves on the screen. The computer must constantly monitor the mouse's movement; it must calculate where the arrow should be and draw it. All of this is done so quickly that the arrow's movements appear to be synchronous with the mouse's movement. This operation may be said to take place in real time.

As computers have become faster, increasingly more functions occur in real time. Because of this development, the computer is often used in "live" performances of music. Synthesizers today are specialized computers with memory for storing information about different sounds, and are able to communicate how these sounds are to be played and changed.

A controller is something one uses to play a synthesizer. It may be something one strikes, blows in, pushes on, waves in the air, bows, etc. (A keyboard is a controller.) Controllers send messages in a language called MIDI. A computer may also use this language to play music on a synthesizer.

The ability of people, computers and synthesizers to interact allows for many performance possibilities. Computers may be programmed to react to signals from musicians. Musicians may trigger pre-programmed synth sequences while they play other instruments. A computer program can create variations on what a performer is playing, or improvise something new from a given point of departure. We may also use a computer to manipulate sounds that are recorded by microphone. These operations may be done in real time with the right equipment.

Why is it important for computers to be able to work in real time? It is because we want "musical" collaborators who accompany us, who keep up with us and react to our spontaneous impulses. We want the music that we make with machines to be rich in detail and sound natural. In addition to using our minds, we would like to be able to use our physical skills when working with computers. A controller thus serves as a link between human body and machine. The more nuanced movements the controller is able to capture, the more "human" the result will seem.

Working in real time with computers also means that we can improvise in a playful and spontaneous manner. There is no need to consider and plan everything beforehand, we may rely on intuition and insight. The computer records our improvisations, allowing us to edit and finetune, and many composers today work in this way.