The term 'LIGHT TUNE' can be broken down into two crossword solutions: AIR (3 letters) and LILT (4 letters). AIR is a common noun referring to the mixture of gases that make up the Earth's atmosphere. It is also used to describe a light, breezy musical composition. LILT is a verb meaning to move or sound in a cheerful, lively manner. It is often used to describe a type of music that has a light, bouncy rhythm. Together, these two words form the phrase 'light tune, ' which can refer to a type of music that is light, airy, and cheerful.