One of the first pieces of equipment you'll need to record music on your computer is an audio/digital (A/D) interface. The A/D Recording Interface converts audio (analog) signals from your microphone or other sound source into digital data that your computer can record and process. A first time recordist may find the array of available interfaces bewildering, so let's cut through the confusion. Just ask yourself a few simple questions and you'll quickly whittle down the options.