I am trying to add multiple MP3's for a music video. When I add a track it takes the first one, but then doesn't play any of the others. My goal is for it to play 4 or 5 different mp3's, one after the other. Any idea why it only plays the first one?
Assemble your audio track in audacity (http://www.audacityteam.org/)
Then add the assembled audio track as you would normally in Avidemux.
so is this simply an unsupported feature? Why doesn't it work without another program?
Avidemux is not an Audio editor, that is why.
QuoteAvidemux is a simple tool for simple video processing tasks. The keyword here is simple: it does not offer tools like a timeline, multitrack editing, you cannot freely move or splice audio and video clips from various sources. However, Avidemux allows you to do elementary things in a very straightforward way.
source: Avidemux (http://www.avidemux.org/admWiki/doku.php?id=using:quickstart)