Stereo or Mono? Which? And why?

Question

Once again I'm starting a new thread to explain some general audio principles that newbies have trouble with.
There's an issue here that's a bit difficult to explain--the difference between "stereo" and "mono".
You have two ears, so you hear "stereo". Your ears send a left signal and right signal to your brain. Your brain processes the difference between the two signals and gives you a sense of direction. You can figure out where the sound you are hearing is coming from.
Originally, recording technology only permitted mono recording. One microphone, and one speaker to play it back. When you listen to recordings made before about 1962, you are listening to a mono recording. If you have a modern stereo and you are playing back a recording from before 1962, you are getting signals out of your left and right speaker, but the signals are identical. You are just getting mono out of two speakers.
Originally "stereo" meant placing two microphones on something--one to represent what the left ear would hear, and one to represent what the right ear would hear.
However, when you take one microphone and plug it into a recording device, you can only record a mono track. Your recording device might permit you to record what you think is stereo, but in reality you are only recording two identical mono tracks.
A guitar also has a plug that comes out of it that sends a mono signal.
Nowadays we create fake stereo inside the recording device by means of what we call a digital reverb or digital delay. This device takes a mono input (such as from a single microphone or from a single guitar cord) and simulates the sound as if it were playing in a much larger room, with positional information included--placing something in a simulated position in the stereo field and creating a simulated left stereo channel and a simulated right stereo channel.
So if you record one input, and put no effects on it, you get mono. If you run it through a stereo reverb or a stereo delay, you get simulated stereo.
If you put an acoustic guitar in a large, reverberant room, and set up two microphones, one on the left side of the room and one on the right side of the room, and record the two mono mike signals to a stereo track on your digital recorder, then you get real live stereo.
When you play a software instrument in GarageBand, it records it as a stereo signal. What you are usually getting is in fact a monophonic sample that is processed through a stereo reverb, simulating stereo. In some cases, it may actually be a digitally sampled musical instrument that was sampled in stereo, with two microphones, like the example of the guitar in the reverberant room that I mentioned above. Software instruments of drum kits and acoustic pianos are examples of instruments that are usually sampled as real or artificial stereo to begin with.
Beginners think "stereo" is the right way to record, and "mono" is not. But this has nothing to do with the right way to record, and has nothing to do with wheter it's a high quality recording. If you are recording through only one microphone, or only one guitar cord, this is mono, and that's right.

Answer 1

Good points, Wheat. And when you record from several sources, and combine them and mix them, panning things to "set the stage" you get a stereo mix, of mono recordings. SI, the final result is stereo, not necessarily each individual piece of the recording. Of course, a drum kit can be recorded in stereo, as well as some keyboards that are actually stereo. But most things you hear on CDs are a compilation of mono tracks, panned to create the stereo image you hear.