The term musical form 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.
- Schmidt-Jones, Catherine (11 March 2011). "Form in Music". Connexions. http://cnx.org/content/m10842/2.14/. Retrieved 11 September 2011.
- Brandt, Anthony (11 January 2007). "Musical Form". Connexions. http://cnx.org/content/m11629/1.13/. Retrieved 11 September 2011.
- Scholes, Percy A. (1977). "Form". The Oxford Companion to Music (10 ed.). Oxford University Press.
- Middleton, Richard (1999). "Form". In Horner, Bruce; Swiss, Thomas. Key Terms in Popular Music and Culture. Malden, Massachusetts: Blackwell Publishing. ISBN 0-631-21263-9. http://books.google.com/books?id=gY-w68zIQWQC.