The term 'catchy MELODY' can be broken down into two crossword solutions: 'HOOK' (4 letters) and 'MELODY' (7 letters). A HOOK is a musical phrase that is used to grab the listener's attention and make them remember the song. It is usually the most memorable part of the song and is often repeated throughout the song. A MELODY is a sequence of notes that creates a pleasing sound. It is the main element of a song and is usually composed of several different notes. Together, a catchy MELODY is a combination of a HOOK and a MELODY that is memorable and pleasing to the ear.