To get DOOM to run properly with both music and digitized sound effects
on the Gravis Ultrasound:  3 steps.

SOUND

(1) Set your ULTRASND environment variable, and use GF1 IRQ less than 8

    example:  SET ULTRASND=220,1,1,7,5
                                   |_______ GF1 IRQ

MUSIC

(2) Doom requires that you have installed the General MIDI patch set from
the 2.06 Install Disks that came with your Ultrasound (and are also
available via FTP and BBS).  DOOM will find your patches (using the 
ULTRADIR variable) in the MIDI subdirectory pointed to by ULTRADIR.

    example:  SET ULTRADIR=C:\ULTRASND

    (DOOM will look in C:\ULTRASND\MIDI for the patches)

*** NOTE:  Step 3 is only required for DOOM v1.0 / Operating System 0.99 ***

(3) You will also need to copy ULTRAMID.INI into your DOOM directory and
rename it to DMXGUS.INI (or find and use the DMXGUS.INI file).

SETUP

Run the SETUP program in the DOOM directory and select the Ultrasound for 
both sfx and music.  Now run DOOM!