An ocarina is also called a Sweet Potato. A small fipple flute shaped like a potato.

Where on earth did you find a double ocarina? I would love to have one!

One octave tunes ... there are tunes that go from sol to sol and they won't work out for you. The seventh will be flat (okay for some Irish though). You need tunes that go from do to do. First one that comes to mind is the Marines' Hymn (the Halls of Montezuma). == Johnny