I've been playing at a nursing home and a senior center, quite often, sometimes several times a week. They have a piano there, so it makes it easy just to pop in and play....I've found that, rather than worrying about 'song selection', if you can play 'emotionally', your audience will, (and does) relate to times in their lives when THEY lived in those emotions.
I'd suggest taking the time tapping into the 'common denominator' of the heart, rather than 'preaching' to them, in music....they don't care about the struggles that certain types of music (especially political messages) try to promote...but they do respond, and well, to when the music touches their soul.....and reminds them of love, simplicity, and innocent hope....peacefully. They respond to the same spontaneous manifestations of those (per aforementioned) that they've experienced through out their lives.

True story!!

GfS