A part song unaccompanied is a type of vocal music in which two or more voices sing different parts of the same melody without accompaniment. The term 'part song unaccompanied' can also be referred to as a GLEE, which is a four-letter word that is used to describe this type of music. Part songs unaccompanied are often performed by choirs and other vocal groups, and they are usually composed in a polyphonic style.