LAME is an educational tool to be used for learning about MP3 encoding. The goal of the LAME project is to improve the psycho acoustics, quality and speed of MP3 encoding. Note: we provide source code only!
A little more than the command line, a lot less than Midnight Commander, and a home-row-based interface (I don't want to say vi-like, but then again, I just did). This is the file mangler I use, and I thought you might like it. Written in Python.