If you want to join, append, or concatenate multiple MP3’s without packing them into a container (like ‘mp3join’ does), you can do so with ‘find’ and ’lame.’ This example also transcodes down to a mono file (-a) and drops the bitrate to 96 (-b 96) – I was converting spoken word from iTunes default rips.
find . -name ‘*.mp3’ -exec lame –decode ‘{}’ - ‘;’ | lame -a –tt “Title” –tl “Album” –ta “Artist” -b 96 - concatenat.mp3
I was annoyed enough by trying to solve this via google that I figured I’d cache it here for myself and the rest of humanity.