Howdy guys,
Yes, what Djim is suggesting is using SynthFont's "Activate MIDI Input" feature.
This allows you to work in Composer for your editing, and hear the sounds of the soundfont that you want to use through SynthFont. In other words, SynthFont is then acting as a MIDI device for Composer to use for playback of files.
I forgot to mention that bit - thanks Djim
ttfn,
Sherry