A guy in the U.K. wanted to cheer up his dad, a former music teacher with dementia.  And getting him to play the piano usually helps.  So he asked for an old party trick the dad used to do.  If you give him four notes, he’ll improvise a song around them.

The song he came up with was so good that the son posted a video, which went viral.  Then someone arranged it for other instruments . . . and members of the BBC Philharmonic Orchestra played along to it from their homes.

The final version is so good, Stephen Sondheim sent him a video.

Now it’s being released as a single to raise money for two dementia and Alzheimer’s charities.