As far as I can tell after a few days of searching, OpenCV's version 2
does not at all support Python version 3, and other distributions of
Python bindings for OpenCV v2.4.x that I could find do not support
Python3 for this version series.
Adding package mp3cat, a command line mp3 utility which will concatenate
multiple mp3 files, and keep only the audio frames, discarding headers
and so on.