Bill, would you please explain to me, a complete beginner, how this thing works?

Let's say I have one friend in my living room playing harp and another friend playing a flute. They are six feet apart. The computer is in the den, twenty feet away. I wish to make a CD of my friends playing flute and harp together.

We will probably buy a laptop in the near future, so that might make things easier.

What do I do?
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I put this question to a technician at the computer shop, but he just gazed at me in silent despair.