What was the first version of Ardour supporting MIDI-tracks ?
I’m running Ardour on an Ubuntu Studio 8.04 and on an Ubuntu Desktop 12.04 and none of the versions has a possibility to insert MIDI-tracks only Audio-tracks.

Ardour 3.0 addded MIDI. Some distributions chose to call only Ardour 2.x “ardour”, and newer versions have names like “ardour4” etc.

Please note that we do not support versions of Ardour provided by Linux distributions, and several of them have bugs that are not present in the official version provided by ardour.org.