PCI Soundcard support
Solution 1:
The MIDI (and FM synth) devices are not enabled by default, probably because earlier versions of the YMF-7xx chip did not have Plug&Play support for those.
To enable these devices, add a line like the following to some file in /etc/modprobe.d/, most likely alsa-base.conf:
options snd-ymfpci mpu_port=1 fm_port=1