The way I've configured ScummVM, the default is to use FluidSynth
for MIDI, and any game where I want AdLib overrides that setting.
I have set the DOSBox OPL emulator as the default.
However, this causes the game's "opl_driver" setting to be "auto",
which overrides the default setting, and usually picks the MAME
OPL emulator. To counter this, if it sees that "opl_driver" is
"auto", it will check the default setting.
In other words, only use "auto" if "opl_driver" isn't set on any
level. I think this is the behaviour that should cause the least
amount of astonishment.
a3008e8f01