I have two machines running Ubuntu - one has Gnome Ubuntu, the other Xubuntu. Both have been recently upgraded to 14.04. On Xubuntu, Rhythmbox has both a menu and a sort of "settings" button on the upper right-hand side. On Gnome Ubuntu (since either 13.10 or 13.04) neither is visible - and, in fact, I don't know how to access the things that used to be there. For example, I don't know how to change the layout or install plugins. How do I access this functionality in Gnome?

I've attached screenshots of Rhythmbox in both desktops.

Rhythmbox on Xubuntu

Rhythmbox on Gnome Ubuntu