I figured it out. You have to tap on the clef where you want the notes to go, in case anyone else gets stuck on this. When I think about it, it makes sense. The Treble clef is the right-hand on the piano and the Bass clef is the left-hand on the piano. And if I had a bass player, I’d write the Bass clef for him/her and write the piano parts to compliment the Bass parts, or vice versa, bass parts to compliment the piano parts.