Two points, I think, bear repeating/emphasizing:

¥ there are a lot of different populations residing in what some would call "nursing homes" -- with widely varying mental functioning levels, of various ages, and from widely varying cultural backgrounds. You could be asked for "Jailhouse Rock" to "Rachmaninoff" to "Rock-a-My-Soul" to "Rock-a-bye, Baby" to "The Rock Island Line" to "Rock-a-bye Your Baby With A Dixie Melody."

¥ It makes a big difference whether you're doing a sing-along, a concert, or background music.