The concept of an interface isn't limited to converting signals from one format to the other. An interface also allows other kinds of translations, such as human impulses into computer-controller data. The alphanumeric keyboard was the earliest of computer interfaces, allowing people to type data into the computer. The mouse quickly followed, as a different sort of interface, preferable to a keyboard in many graphically oriented environments.

The operating system is what makes your computer work, telling the chips and other mysterious gizmos inside the box what to do and providing colorful and user-friendly screens on your monitor for you to fill in, rearrange, and otherwise play with. Software applications run on top of the operating system and therefore must be carefully written in conjunction with the OS's specs to take advantages of its features and to avoid illegal operations (which result in crashes).

To get your computer recording system to work, you don't need anything other than the multimedia speakers that came with your computer or those you can purchase for less than $30 in any computer store. However, keep in mind you're creating music to be listened to from a CD and over a stereo system, not necessarily a desktop computer.

In order to record music onto a computer, it would be useful to be able to make music in the first place. You can get data into a computer in a variety of ways, but because we're talking about music, let's examine how you would use a musical instrument as an input device, even if that is a funny name to describe an eighteenth-century Stradivarius. A computer doesn't judge your musical talents or tastes, or the aesthetic quality of an audio signal.

It helps to think of cables not by their length or their color but by their function. A cable transports a signal, of course, but in music and audio recording, a cable carries only one of three types of signal: audio, data, or power. (A power cord is a fairly straightforward concept, so we don't need to devote much thought to it.) The type of connector at the end of an audio or data cable further defines its function within that category. Following is a look at both the connectors and the functions of the various cables.

Audio cables