My girlfriend used to work in a nursing home. One of the old ladies had been the director of a church choir before getting dementia. She spent almost the whole time slumped in a chair without speaking a word.

One day they happened to have "Songs of Praise" on (a radio programme that's basically all hymns). She suddenly stood up with tremendous dignity and began to conduct the radio, following every inflection of the performance and finishing exactly with the broadcast choir, arms outstretched and looking up into the distance out of the window.