The term musical form (or musical architecture) refers to the overall structure or plan of a piece of music, and it describes the layout of a composition as divided into sections. In the tenth edition of The Oxford Companion to Music, Percy Scholes defines musical form as "a series of strategies designed to find a successful mean between the opposite extremes of unrelieved repetition and unrelieved alteration. "

Musicologist Richard Middleton describes form through repetition and difference: difference is the distance moved from a repeat; a repeat being the smallest difference. Difference is quantitative and qualitative; how far different and what type of difference. According to Middleton, musical form is "the shape or structure of the work. " In many cases, form depends on statement and restatement, unity and variety, contrast and connection.