The origin and history of Unchained Melody

This song was written by by Alex North with lyrics by Hy Zaret.  It was actually written and promoted to Bing Crosby, who did not perform it.  Twenty years later it was song for a prison scene in a movie "Unchained" and that is how it got its name.  It has been covered by many people over the years, almost 500 versions.  The most famous is by the Righteous Brothers, which version was used for the movie Ghost.