Thanks again for your help. I have just spent an hour struggling with BIAB and I'm beginning to think that my plan is too simple for BIAB to deal with. I don't want an accompaniment. I don't want a style. I don't want tracks. I just want to enter a simple single note line, to indicate octaves, or a scale and that's it. I just want to hear it as a flute or sax. After I can play along with my Theremin I want to increase the speed or change the pitch.
I have read the tutorials on the notation window but I can't figure out how to scroll down into the bass. On my screen I have a whole treble staff but only the top line of the bass staff. If I click on bass part I get more of the bass staff but not all of it. Only four lines are shown. The lowest note I can enter is B3. I would like to enter A3.
Also my screen doesn't look like yours. The top right quarter of my screen has a mixer. I don't see a key icon as shown on your screen shot. This may be because we have different versions. I have 2014. Sorry, but I am an absolute beginner on BIAB. If there are help files or posts I should read, please point them out.