There was a comment in the new hymnal thread about older people in long-term care hearing and responding to music they remember. This is something that has struck me as well; as my grandma was getting older, it got pretty hard to have conversations with her — her mind and mouth just weren't connecting right. But I could bring my guitar and play some hymns, and while she didn't remember all the words, she remembered a lot, and they totally resonated with her.
Mark H observed in the other thread that as congregations grow less denominational, this idea of a core set of songs that most people can carry into their old age is becoming impossible across a denomination. I might go further and say that as people seem to become more "nomadic", it's extremely hard even within a single congregation, especially those that place a lot of value on playing a lot of newer songs.
What do you think — is it possible to inculcate these kinds of songs for people to keep with them as they age? Is it worth putting effort into? Are there practical things that you're doing to try? What songs do you think fall into this category for your congregation?