We mention music and song so often, and it does seem to have powers of its own. For those of you who have not seen this:

 The following video features Naomi Feil who teachs Validation Therapy.  In this video, she is visiting an Alzheimer's patient far into late stage and pretty much non-responsive, and what happens is stunning.

Please watch the video to the very end; it takes time to see the result; and oh yes, a kleenex or too may be needed:

https://www.youtube.com/watch?v=CrZXz10FcVM

J.