I've been thinking what to do with my old piano with keys that don't work that has out of tunes strings that are too far out of tune ever to be tuned back. Firstly, I've learned that 'out of tune' means different things to different people. Some say that out of tune means when a pitch is different to the standard, accepted frequency, others when the tone [timbre] doesn't sound right to them or both of these things. There are loads of other variations on these points! Anyway, there are a few options....not playing the piano with the black and white keys but allowing the strings to sympathetically vibrate with the sustain pedal on. Playing the piano as usual and not worrying if it sounds 'out of tune' - putting thumb tacks on the hammers to make a honky tonk sound - out of tunes strings are a benefit to the honky tonk tone. Or, perhaps the best option for my old piano which is probably around 90 years old and has been left to languish for years - remove the frame and use it as a garden ornament. I went on holiday to a beautiful, communal farm in Cornwall this summer and the people that lived there had done just that and had created a beautiful garden space complete with fish pond and an old piano frame. Lovely!