I want to keep a piano outdoors. Thoughts?

Sounds decorative! Set -up outside on cement blocks, preferably lay small pebble river rock first. You may want to lay a coat of exterior polyurethane on it to protect it from moisture. Cut a 12" x 12" round or square opening on each end and fasten screen mesh over it from the inside (tip it),. This will allow the air to circulate through and keep the inside dry. This option is the best thing you can do for outdoor display and use. Do you have a cover for the piano keys? The one that flips down? Either way make a separate cover for these keys and use mat'l like foam rubber covered with a moisture grabbing material. The piano key actions which are located inside are very intricate, made from a very durable hardwood and will resist moisture and the piano wire is stainless steel so these items should be ok. If you are concerned about these, spray all the key actions with a polyurethane. An awning over the blessed thing is a must but make sure it is large enough so the rain water drips off without splashing onto the piano. Set some D-Con inside and check the inside once in awhile. For a little xtra added touch, wrap the legs of the piano (if there are any) with a decorative tape. I have seen various tape designs at craft stores. Before foul, cold, snowy weather season tarp the piano but keep the vent openings clear for air flow. This might require removing snow. I just thought of something! Make solid covers for the vents when playing (removeable) for proper sound. That's important! You can make these 2 covers so they slide up or down to open and close. But, remember to keep them open when not is use. Now, with this all done, you can enjoy!