Thanks for your response. Let me answer your two concluding questions first.
When I look at the contents of "folder A." on my desktop, I can see all the files.
When I am in mucommander, and I am looking in the left panel, I am positive that I am looking at the contents of my iTunes music folder. Everything is there, including new music files that I downloaded last night as well as the Teaching company files I copied last night. The ONLY THING that is not in that left panel are the Teaching Company files that I tried to copy this morning. Here are the steps I took in attempting to copy the files. First, I'll take you through the steps I followed last night. Then, the steps I followed unsuccessfully this morning:
1. Last night, I copied several files off of a CD that I had purchased from the Teaching Company into iTunes.
2. I converted those files while still in iTunes from AIFF format to MP3 format (160 Kbps and 192 Kbps); I had to convert them to MP3 format because the USB port (JVC KD-R900) will not play the files in their native AIFF format.
3. I opened muCommander, navigated in the left pane to the music folder where I saw all of the files, including those I had just converted to MP3 format.
4. I copied all of those converted files into the right pane (where I had navigated to my thumb drive).
5. I copied those files onto my thumb drive and stripped the resource fork from those files one at a time.
6. I played the files fine on the JVC using my thumb drive.
Now, Here's what I did this morning.
1. I did exactly the same thing as above.
2. I did exactly the same thing as above.
3. I then opened muCommander. In the left pane I navigated to my iTunes music folder. There I see all of the files (including those I successfully copied from the same CD last night). What I DO NOT SEE in that left pane is the new set of files which I copied from the same CD this morning (remember, I CAN see those teaching Company files when I'm in iTunes). I am importing those files from that CD in exactly the same manner as I imported them last night. I am converting them to MP3 format in exactly the same way as I did last night. They simply do not appear in the left pane of muCommander either in their native (AIFF) format or in their converted MP3 format.. I have been over the procedure so many times to make sure I'm not leaving out of step. Any help would be greatly appreciated.
4. I tried downloading muCommander onto my MacBook Pro, and repeated steps one through three, but with no luck. I got exactly the same results on the MacBook Pro as I got on the Mac Pro.
Thanks for your help, Nicolas