The SoftSynth

Hi, I download the source of allegro
after that i looking for midi synth from allegro and the good(very bad) 
news is :
Allegro don't use their own softsynth but for BeOS that just use the 
BeOS SoftSynth and for other platform that just pass the data to the 
corresponding OS.

I may be wrong then tell me what file I must read. 

Good night
A+
Jerome