Used to be commercial then set free, I grabbed this in like 2006 or 2007 from the Bluespook site it has unlock code you enter upon first opening... A different way of MIDI composition with an emphasis on features for a humanistic feel... Comes with examples which are rather basic but sounds good if you have say the Yamaha XG WDM SoftSynth or similar or perhaps run it thru a MIDI port to pretty much anything else... You can also export MID file out of it so you are not locked in... 'Tune of a Different Drummer' MIDI program...
https://archive.org/details/mamba-2.0
https://archive.org/details/mamba-2.0