When the Slinky debuted at Gimbels Department Store in Philadelphia in November 1945, it cost $1.00 (equivalent to about $17 today). Richard and Betty James sold out their entire initial stock of 400 units in just 90 minutes.

The tongue is widely cited in anatomy as the only muscle in the human body that is attached at only one end. Rather than being anchored to bones at both ends like skeletal muscles, the extrinsic and intrinsic muscles of the tongue function in a "free-floating" manner.

The King of Hearts is the only king in a standard deck of playing cards without a mustache.

A section labeled fortississimo (marked as fff) should be played extremely loudly. It is much louder than fortissimo (ff). It is one of the loudest dynamic marks in music.