Use MIDI software "soundfonts mapping"

This is a quick "how to", to use softwares installed like explained on this post:
- launch Jack Audio Connection Kit daemon with options according to your configuration (let's said you are using ALSA)
jackd -R -d alsa
The -R option is used for "real-time", I explain it into my next post.
- launch a fluidsynth GUI frontend
qsynth
- setup the wished soundfonts (there we're using the path of the fluid R3 soundfonts), setup->Soundfonts->Open and selects the path /usr/share/soundfonts/FluidR3_GM.SF2 (under Fedora 8),
- finally launch Rosegarden and play MIDI files or Rosegarden Studio of your choice
rosegarden
- you may need to update configuration of the MIDI devices, Studio->Manage MIDI devices.

N.B.: those instructions have been performed (at least) under Fedora 8