Props
Another possibility.....
If you are comfortable not using a general midi synth but using one where individual tracks are set (like Kontact), you could use Sforzando that comes with BIAB 2017 and soundfonts. There are heaps of soundfonts on the net for free.... some are really good and some are really bad.
Also some instruments translate and play back really well as midi (e.g. piano, organ, strings, etc.). Some others don't always sound as good when interpreted as midi. For these, the instrumental nuances that define 'realism' require advanced midi engineering skills and the midi file in use might not always contain such data.
Lastly, if you want to learn how to drive midi, this is much easier done in Realband than BIAB (as rharv has already mentioned).
Regards
Noel