[doggit]

I probably shouldn't have said 'down beat' and rather just 'beat' or 'pulse'.

Let me try to explain with a couple of simple examples using a standard click:

Lets say you want to practice you favourite 4/4 groove, so you put on the metronome at 120bpm and start playing, no problem. The metronome is clicking on every beat, 1 2 3 4.

Now try setting the metronome to 60bpm, except now you're still going to play at 120bpm. So while you are playing the same groove at the same tempo, the metronome is only clicking on beats 1 & 3, i.e. every second beat. Not too hard, but already a good exercise because the gaps between clicks are longer, forcing you to feel the spaces between more accurately.

The next step is to flip the metronome around in your head so that it is only clicking on beats 2 & 4. So it's still clicking at 60bpm, you're still playing at 120bpm, but there is no more down beat. One way to do this is to starting counting from 2 (2 1 2 3 4 1 2 3 4 1...) until you can feel the down beat, even though it's not being supplied by the metronome.

The software takes these basic concepts a lot further using displacement and polyrhythms to provide all kinds of patterns to play with, not just 1 & 3 or 2 & 4.