Ben said:
I shouldn't post with only one eye open. I think it should be:
At the dos prompt: join file1.mp3 + file2.mp3
I think you still have an eye closed.

This is incorrect.
In some versions of DOS, join was a command that allowed you to mount
a drive as a directory on another drive. Has nothing to do with
copying files.
I think what you mean is
copy file1.mp3 + file2.mp3 combined.mp3.
However, this does not work for mp3 files. I have seen this "copy and
concatenate" technique mentioned frequently in ACF for mp3 files, but
it doesn't work for me. The files are copied, of course, but I can't
get them to play in a player. I wouldn't really expect this to work,
since mp3 files contain more than just the music, they contain ID
tags, and encoding information. So just concatenating the files isn't
likely to give you anything useful.
Terry