Concatenate or Join MP3 files

You can join multiple MP3 files into a single MP3 file with the following command:
$ cat 1.mp3 2.mp3 3.mp3 > all.mp3 <enter>

In Windows, the below command should work:
C:>copy /b 1.mp3+2.mp3+3.mp3 all.mp3 <enter>