TOM: That'a a loooooonnnnngggggg time to play solo.

    You didn't indicate if you're US or UK. I don't know if the songs will fit as well in UK.
    In a situation like yours, I'd take a song book or two, full of three chord songs. I would chord check all of the ones that you select, to get the right key for each song. Most of them will be in one or two chords, more than likely.
    Ask the social director at the nursing home a few questions, before you go.
    1. Who have they had there before that the residents enjoyed?
    2. What songs or kind of songs did they like??
    3. Does the facility have any songbooks?? Can you borrow one
         beforehand?
    4. If they don't have songbooks, see if they will run off a few
       copies of your songs. Get them "blown-up" at a Kinko's or
       similiar printer, prior to going. They'll reimburse you/
    5. When you start, ask the residents and their attendants
       if they have some songs in mind.

    I use lots of old gospel and folk songs. If things get really dragging, I do something like "Billy Boy" with nonsense verses about people in the audience.

Steve