Patriotism tends to run high among senior citizens, so patriotic songs are likely to go over very well. Patriotic songs are also widely known, so you probably won't have to worry about whether or not people know the lyrics. Such songs include "America the Beautiful," "God Bless America," "America," "This Land is Your Land" and "God Bless the U.S.A."
Folk songs are simple heart felt songs. Many of the folk songs that were sung decades ago are still learned by children today. These songs tend to promote good feelings and remind us of times gone by. Such songs include "Red River Valley," "Down in the Valley," "The Yellow Rose of Texas," "You Are My Sunshine," "Moon River," "Shenandoah," "Oh, Susanna," and "Suwannee River."
As opposed to folk songs, some of which are over a hundred years old, popular songs are those that were current during the first half of the twentieth century. These songs were on the radio when senior citizens were young and are likely to bring back happy memories. These include songs from artists such as Frank Sinatra, Elvis, Ritchie Valens, Bing Crosby, Dean Martin, Ray Charles, Johnny Cash and others.
Holiday songs have changed little over the years and thus are very well known especially Christmas songs. Nothing stirs Christmas spirit like singing Christmas carols. Such songs include "Jingle Bells," "What Child Is This," "Must Be Santa," "Silver Bells," "Silent Night," "Here Comes Santa Clause," "O Holy Night," "Rudolf the Red Nosed Reindeer," "White Christmas," and "Winter Wonderland," "Joy to the World," "The Twelve Days of Christmas" and "O Come, All Ye Faithful."