GIYF (Google Is Your Friend)

http://ubuntuforums.org/showthread.php?t=220313

The one I use is called "Sound Converter," which is a GUI for ffmpeg, which does
all the heavy lifting.

The programs they talk about in the link below but SOX and Sound Converter
can't convert to MP3. The description in Synaptic says that both of these
can do it but I have already DLed and tried both of them. In the docs for
SOX it mentions a big list of audio formats it can handle but MP3 is not one
of them.

http://ubuntuforums.org/showthread.php?t=220313

i have used sound converter to convert ogg to mp3 for
years. You do need to install the codecs but you need those to play
mp3 too.

Did you install the restricted extras?

I have installed gstreamer. Is that the one you are talking about? The
readme or something that came with SOX does not list mp3 even though
Synaptic say it can. May be they got in some hot water about the mp3 code
and removed it.

No, I meant the restricted extras.

Better yet, have a look at this web site:
blog.thesilentnumber.me/.../...ll-guide-what-to.ht\
ml

You can also do it from Nautilus file manager right click if you have the
nautilus-script-audio-converter in the repositories installed.

I have tried that too. The problem I have is that after Nautilus installs it
I cannot find it to use. What name do you think it goes by and/or where is
it located. Doing a "sudo updatedb" then a "locate
nautilus-script-audio-converter" give no useful file names that should be an
executable. This is based on them being in places like doc or lib
directories.

It is on the right click menu in Nautilus. Right click on an audio file and
you should see it under the Scripts submenu as Convertaudifile.

audacity....................................

Going to Nautilus and DLing nautilus-script-audio-converter was no problem.
Matter of fact I actually found that converter myself and installed it. Then
in Ubuntu I could not find it. I didn't see a GUI icon for it. In terminal
doing a updatedb then locate, with locate I tried several search arguments.
I found where lib and docs, things like that had been install on my computer
but nothing was in a place where I would expect to find an executable.

Where might that be, better yet what name do I call it to execute it in
terminal or a GUI icon?

The more I think I know about Ubuntu the more it proves me WRONG.

If it's the odd file you want to convert, rather than en-masse, maybe you
should try
http://media-convert.com/

<http://media-convert.com/>it's free, and doesn't require any installation -
and is os independent, so can be used from any pc.. Obviously not so handy
if you've got 100's of files to convert..