Joe,

top 100 lists are online for every year going wayyy back. If you want to zero in on the songs that appeal to a particular age group, that's a good starting point. Most people retain an affection for Whatever music was popular the year they graduated from high school, and through their 20s.

Here's a link to top 100 lists starting in 1950:
http://www.musicoutfitters.com/topsongs/1950.htm

people between the ages of 65-80 should at least be familiar with these songs. Age 68 would have graduated from HS in 1950, and up to age 80 would have been young adults that year

(for subsequent lists, just change the year)
I've printed all the lists and am in process of learning the top 10 songs from each year in order to be prepared for every age group



Also many of the people here who play for a living have said that the crowd tends to tell you what they want to hear by their requests. Just listen to what they say and act on their requests to hone your set list for any given venue.


Also, if you approach the staff at homes and retirement communities etc, they can tell you the average age of their residents, and what other entertainers are playing. (you probably won't be the only one)

https://www.dropbox.com/sh/ey71h8ep047758h/AAC12jNM0Hz9Q8zsh5iDeqNHa?dl=0