Playing at nursing homes can be fun, but the song list is important, as many on this thread have noted. Here are some of the songs we play that get a nice reception for most 'older' venues we've tried. We usually end with Goodnight Irene or So Long It's Been Good to Know You.

You Are My Sunshine
Ain't She Sweet
Georgia On My Mind
Home On the Range
My Blue Heaven
Jambalaya
Nobody Knows You When You're Down and Out
The Old Gray Mare
Pack Up Your Sorrows
When You're Smiling
On the Sunny Side of the Street
Take It Slow and Easy
Lulu's Back in Town
I've Got a Lovely Bunch of Coconuts
Five Foot Two
Ain't We Got Fun
Bill Bailey
The Happy Wanderer
Goodnight Irene
So Long, It's Been Good to Know You