Slow Dance is the basic slow motion movement. Double Trouble makes the object look as though it split into two objects as it moves.

In this episode, we trace the history of slow dancing from its origins in partner dances like the waltz to the modern “zombie sway” seen at middle-school dances and high-school proms.

But there are exceptions, and Patricia Delgado, who stars in the new music video for the National’s slow-simmering ballad “Dark Side of the Gym,” is one of them.

Meryl Comer talked about her book, [Slow Dancing with a Stranger: Lost and Found in the Age of Alzheimer's], in which she reports on the effects of Alzheimer's, the degenerative brain disease that ...