I am making a black piano and would like it to look a little shiny. How do I do that? I don't have an airbrush. Thanks!

If I remember correctly you have to wet it....just lightly. Maybe use a wide, flat art brush or mist it w/a spray bottle?
OR water down some plain or black piping gel?

You can use confectioner's glaze. But don't know where you can buy it in the US.

Nicholas Lodge sells confectioners glaze on his web site. Or you can buy edible spray laquer from CK.

Steam it.

There is a recipe on CC for edible varnish

How big is the piano? For small pieces, I just paint my gp with black gel paste. Even when it dries, it stays relatively shiny. Otherwise my black gp looked so dull. You can dilute it a bit, but again that depends on your gp piece and if it's safe to get it wet (after all of that effort to get it dried out!) I also did a 45" "vinyl record" out of fondant with this method.

Certainly the edible laquer or confectioner's glaze will work but I was afraid of the glaze, haha I am afraid I'd stick myself to my counter with it.

You would want to steam it and it will give it a light sheen.

You need to make sure the steam is strong - like from a tea pot, and you do a quick pass through so you don't wilt the sugar paste.