Thank You for this answer.
I suppose that you send to this link ?

http://www.pgmusic.com/tutorial_realdrums_stylemaking.htm

I will work with it.
Actually when I have to learn Latin, Carribean or African tunes, I switch my computer to Linux and use Hydrogen, but, doing so, I loose the harmonic part.
My hope for the Graal would be to have in BiaB a way to choose the rythm, the pulse, as fine as it is to indicate chords. Because playing music seems more challenging to me ...
From France under a lot of snow.