MELODIC SYLLABLES are a type of poetic device used in literature and music. The two crossword solutions, LAS and LALA, are examples of melodic syllables. LAS is a three-letter word that is used to create a rhythm or melody in a poem or song. LALA is a four-letter word that is also used to create a rhythm or melody in a poem or song. Both words are used to add musicality to a piece of writing or music.