Thank you to Clemens for the offer to help, but I just found my problem.
Since DOSemu's sound layer is mostly an emulation of the SoundBlaster, I
thought I needed a Soundblaster Midi driver.  It looks like Voyetra has
a VAPI driver for MPU-401 (
VAPIMPU.COM), which works perfectly in the
emulation at IRQ9, port address 0x330, and that's the driver I need.  I
just now tried this, and Midi i/o to real hardware ports works.
So I have Midi in DOS now on Linux.  Wow...isn't techology moving
forward?  The moral of the story here is that if you work hard, you too
can upgrade now to MS-DOS.  Now if I just had a OS360/CICS mainframe, my
studio would be just like all the cool kids these days, and they'd stop
calling me names.
Thanks again ...
--
- Brent Busby   + ===============================================
                + "The introduction of a new kind of music must
-- Studio    -- +  be shunned as imperiling the whole state, for
-- Amadeus/  -- +  styles of music are never disturbed without
-- Keycorner -- +  without affecting the most important political
-- Recording -- +  institutions."    --Plato, "Republic"
----------------+ ===============================================