I have lots of music and would like iTunes to randomly add it to my iPhone. However, I don't want it to fill the phone completely as then I can't take pictures, so I am trying to limit it, but the control to do this has disappeared and I can't find it. On the referenced page it shows the control on step 4, but that is not visible when I click on Music under my iPhone device. This is also not explained in the online manual (or its well hidden).
Please help. Thanks!