Actually, I've been getting requests at assisted living, nursing/rehab centers, and retirement homes for years for songs by Kenny Rogers, The Beatles, Peter Paul & Mary, Chuck Berry, Elvis, Vince Gill, Reba McIntyre, B B King, John Denver, Simon & Garfunkel, Johnny Cash, and many other recording artists from the '60s & '70s.   

I do get requests for songs that were popular in the '20s, '30s, & '40s a lot (even if some of those songs were written or collected decades earlier) , but it's really for the "standards" from those eras -- the songs that have been played and maybe recorded by musicians across a number of decades.   

And it is important to be aware of the often wide range of both ages and levels of cognitive functioning that you'll find in many "nursing homes."