BLASTER SETTTING IS WRONG, MIDI PORT IS MISSING:
CURRENTLY BLASTER IS SET TO:
SET BLASTER=A220 I7 D1 H5 T6
THIS SHOULD BE:
SET BLASTER=A220 I7 D1 H5 P330 T6
Some applications depends on the P330 being there, this sets the midi port in the blaster settings.
Without it these applications will not run.
DOSBox is primarily for running DOS games, and so far no game has been found to need (or work better with) the MIDI port parameter in the BLASTER environment variable, which is why it has not been added. Because DOSBox emulates an MPU-401, it may even be beneficial to not suggest that the MIDI port is on the (emulated) SoundBlaster.
That said, adding the MIDI port parameter would be trivial to implement, but it would need testing to be sure that it does not cause a regression in any game. Keep in mind that the few users that might need it for an application can add the parameter themselves with a batch file or so.
Please name the applications that need the MIDI port parameter -- it will help with considering the feature. I have used a number of MIDI sequencer programs in DOSBox, and none has needed the port parameter, so I suspect it is not a common requirement.