Open Sound System

Open Sound System packages on the edge.

Add the PPA, update package lists, and then:
sudo apt-get install oss4-base oss4-dev oss4-dkms oss4-gtk
sudo dpkg-reconfigure linux-sound-base
(select OSS)
Make sure any USB audio devices are plugged in and reboot.

To test:
osstest

If sound in Flash doesn't work,
sudo apt-get install flashplugin-flashsupport-oss
or
sudo apt-get install flashplugin-flashsupport-oss-32bit
for amd64 with 32-bit Flash player.

In case it turns out to be a FAIL:
If the machine locks up on boot, the recovery boot option should still allow booting into root console.
Removal:
sudo apt-get purge oss4-base oss4-dev oss4-dkms oss4-gtk
sudo dpkg-reconfigure linux-sound-base
(select ALSA)
reboot

NOTE:
Upgrades can be flaky, so, better to just
sudo /etc/init.d/oss4-base unload
sudo apt-get purge oss4-base oss4-dev oss4-dkms oss4-gtk
sudo apt-get update
sudo apt-get install oss4-base oss4-dev oss4-dkms oss4-gtk