I have a track with keyboard and another track with bass.
When i click the loudspeaker symbol, and then click on one of the tracks, the recorded sound plays fine.
However, when i click the green play triangle to listen to both tracks - nothing happens but silence.
So -once again, the last resort (reading the manual) did the trick.
Made my first recording with Ardour in JAD1.0. Got the inputs and outputs right in qjackctl as suggested.
This is really fantastic, it is unbelievable what you can do with just a qwerty keyboard and the build in synthesizers and drum machines.
A salute to all you brave people who made this possible!