Sort:  

The Beatles song "A day in the Life" has an extra high-pitched whistle, audible only to dogs. It was recorded by Paul McCartney for the enjoyment of his Shetland sheepdog.

This post has received a 38.74% upvote from @lovejuice thanks to @steemcurrency. They love you, so does Aggroed. Please be sure to vote for Witnesses at https://steemit.com/~witnesses.