How to create a text file listing of all files in a specific folder?

You can use the dir command. First navigate to the folder with all of the files with command prompt, you can copy a directory from explorer and paste it in by right-clicking if you don't wish to type.

To exclude directory names but recurse into subdirectories:

dir /a-d /s *.mp3 > mp3s.txt

although the above will show hidden files (thumbs.db among other things from album art) so you may want to hide those:

dir /a-d-h /s *.mp3 > mp3s.txt

both of the above approaches will make a text file called mp3s.txt in your mp3 folder.

For a GUI approach, you can use DirPrint, The How-To Geek recently wrote an article on it:

For those who use Total Commander, there are menu items for this:

• Copy Selected Names To Clipboard
• Copy Names With Paths To Clipboard
• Copy to Clipboard With all Details
• Copy to Clipboard With Path+Details

It's in the Mark menu and work with selected files. Select them all ("+" on the numeric pad, "*.mp3" as filter) if you need to copy the names of all MP3 files in the directory.