Jorge.
could you please describe your problem in more detail.
i'm on windows but same midi principles apply on mac.
midi is just computer data jorge.
ie like instructions a teacher might give to a class of students.
for example data on when a note at a certain time point is to be played or say a program change like play a trumpet now instead of the sax previously. so its a stream of computer DATA. nothing more.
in summary completely different from an audio recording in a recording studio of a live sax player being recorded.
HAVE YOU WATCHED THIS PG VID THAT ADDRESSES NO SOUND
(in the mac faq's.)
https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=613706#Post613706if not done so check out all the pg mac faq's//vids.
THUS ...
in order to turn the computer midi data stream into audio in band in a box or reaper or logic .....
(i'm a biab and reaper user) you need to load up a plug in or instrument of some sort. ie a piece of software that is programmed to convert the midi data stream into real audio.
there are lots of resources/vids here at pg on useing midi jorge.
as well as on the net and you tube includeing a nice series of midi vids at reaper.fm . (see videos section on main page right hand side.)
if your new to midi i suggest also you get a book on midi that describes all the different nuances of midi and functions in great detail.
in summary you need to load a plug in or instrument to convert midi to audio. whether on a global level or on an individual trak.
for example in reaper or logic.
please could you post a pic of your preferences settings in band in a box mac so mac people can help further .
cos if your not hearing things still i suspect a setting in band in a box/and or logic etc hasnt been set.
hth.
best
oldmuso