Timidity:

sudo brew install timidity
mkdir /usr/local/Cellar/timidity/2.14.0/share/
ln -s /usr/local/share/timidity/ /usr/local/Cellar/timidity/2.14.0/share/timidity

Download TiMidity++ GUI from here

Download instruments, and install.

touch /usr/local/share/timidity/timidity.cfg