A 2nd instrument for the traveling Pianist

Hi all,

As I believe you've noticed, pianos are not the easiest to carry around. I'm about to travel quite a lot and want to be able to still play (mainly practice chord progression and scales). I've been thinking taking an ocarina with me as I have a friend I can borrow from. Do you think that other instrument might be better? I need something small and light as I am going to carry it.

Thanks