Are the simplest melodies the best?

Let's be honest. Writing a good, memorable, immediately singable melody is challenging. In fact, it's funny how often master composers and songwriters of all times and all genres think some of their finest melodies are of no consequence. One such melody that comes to mind is "The Long and Winding Road" by the Beatles. Even though he shares the writing credit with Paul McCartney, John Lennon hated this song. Yet, it is often included on "favorite" lists of Beatles songs. This is also true of...