I'm using Ubuntu 16.04

I have launch() working in Windows, but I'm having issues under Linux.

First I tried:
launch("/usr/bin/lame", "/home/name/test.wav", "/home/name/test.mp3");
nothing...

Next I tried:
launch("lame", "/home/name/test.wav", "/home/name/test.mp3");
nothing...

According to the reference, one of these should work... "On Linux, it first tries gnome-open, then kde-open, but if neither are available, it sends the command to the shell without any alterations."