FluidSynth is included on openSUSE installation media, so use YaST or zypper to install it. You may want to install Qsynth GUI frontend to FluidSynth, that can be found in Packman repositories.
The default installation has no soundfonts so you have to download some. A good source is http://www.personalcopy.com/home.htm where one can find Unison.sf2.gz and PersonalCopy 5.1f.sf2.gz.
Play MIDI music
fluidsynth -a alsa -l <soundfont_file> <midi file to play>
- Man pages in text mode terminal or GUI console.
- Man pages using Konqueror by typing in Location input field man:fluidsynth.
DISCLAIMER: SoundFont(R) is a registered trademark of E-mu Systems, Inc.