a stereo track is simply two mono tracks...one for each speaker. This is why you have to playback stereo music with two speakers. What happens when you pan a track is it's affecting the volume in one speaker or another. Take a simple mono track of a voice for example. If you pan it in the middle the voice is coming out of both speakers at the same volume. Now as you slowly start to pan it left the sound waves aren't really moving in front of you, the volume in the right speaker is just decreasing while the volume in the left is increasing. It gives the affect that something is moving in front of us.
A stereo track can be panned if you want it to be...but then you'll just be panning the individual left/right channels that are supposed to be going to their respective left/right speakers. So now as you pan the left channel over to the right, you'll be losing signal in the left speaker and it will start to sound weird. Try it...bring in a stereo song and mess around with the panning.
Hmm... I'm not sure I know what you mean by "stereo reverb" and "stereo chorus." Aren't reverb and chorus just effects that you can put on either a mono or stereo track? I didn't think the effects themselves were mono or stereo.
Reverb and chorus can be used as spatial effects. Typically they are applied to mono signals and output a stereo signal in return. When applying reverb we generally are trying to get the signal to sound as if it's in a room of some sort. Similarly to the room you're sitting in, sound bounces all around your ears. So applying reverb in stereo we try and emulate what a room would sound like.
Again, try it yourself. Apply a stereo reverb to a mono track and listen to it...then do it again with the same settings but keep a mono signal. You'll notice it doesn't sound the same at all.
So say I lift a sample from a song or download it off of a website but I have no idea who recorded it. I know how to determine if it's a stereo file, cuz I just load it up into an audio editor and see that it has two channels. But how would I determine if it has a stereo effect on it?
simply by listening to it. Does the sound coming out of the speakers sound different in each speaker? Watch the meters...are they bouncing up and down at different levels? If yes, then it's in stereo.
If the engineer panned everything in the middle and then made a CD of the song. Each speaker channel would sound the exact same and the meter levels of the music would be the exact same.
Since you mentioned keyboards... How would you go about panning a piano track? Like for instance I have a project consisting of a looped drum beat, vocals, bass and piano (MIDI controller with a piano patch). The piano plays the "main melody" throughout the song. I'm not planning to add any more instruments/tracks. So far I've got everything panned straight up the middle, simply because it would sound weird to me with the piano or bass panned L or R. But from what you guys are saying, it is amateurish to pan everything straight up the middle. Should I pan the piano anyway a little bit L or R anyway? Or should I set it up in Logic so that some notes are panned one way and some are panned the other way?
if you're working with loops...typically they are already set up to playback as is. So if you bring a piano loop in, and it shows up as stereo in your program...if you leave the panning sliders so that Left is left and Right is right, it will sound the way it was intended too by the engineer who recorded it.
Now if you bring a bass track in and it's ALSO a stereo track...but after you listen to it you don't hear any difference in the channels and the meters are bouncing up and down together, well then you have a mono signal that is playing back on a stereo track. This is fine and is very common with loops that were imported off of audio CDs. Since the audio CD standard burns stereo CD's always...the engineer has to accept the fact his mono bass tracks are going to be converted to stereo. They still sound the same though.
Now, if you want to change the way your tracks are panned for your purposes...do so. There's no harm in panning it the way you want to. But for the most part, pianos that have been recorded are panned off to the L/R a big and bass tracks are panned in the middle. Lead vocal tracks are also panned in the middle and typically snare and kick drums too. But these aren't set rules. This is audio, so use your ears and your own judgment as to what sounds good to you.