Musical memories seem to lie deep in the brain, possibly because they're stored in multiple locations. That's why music has the power to soothe ruffled emotions and even help someone with moderate-stage dementia seem to briefly "snap back" to his or her old self, if only for the duration of a song.
Pull together a "bad-day playlist" of music that you can use when you and your loved one with dementia are having a hard time getting along or making it through a bath or a meal. Better still, create two lists: one to help energize if lethargy is an issue, and one to soothe and calm on days you're coping with agitation.
What to include:
The person's absolute favorites (often that's what was popular in their teens or 20s)
Any sort of music you've noticed has an especially calming effect, whether it's Christmas music or random New Age compositions
Spiritual music, such as hymns, for an avoid churchgoer
Tunes with catchy refrains you can sing along with, such as old TV show theme songs (search iTunes)
Soundtracks to musicals, such as The Sound of Music or Anything Goes