[ I - IV - V - I ]: Introduction
|Cadential structure in symphonic music is a series of variations on a simple theme - a module - the harmonic progression [I-IV-V-I] (Example 210.1, in C major).
|I may not be consistent in my terminology. A chord is the simplest harmonic unit. A chord may be in root position or in any of those permutations called (inaccurately) inversions. Whatever the inversion of a chord, the harmony remains the same. A root position tonic triad and a first inversion tonic triad are both tonic harmonies.
The concept of function is more complex. In cadential structure, there are four structural functions - the initial structural tonic [I-], the structural subdominant [-IV-], the structural dominant [-V-], and the final structural tonic [-I]. The structural dominant and the final structural tonic must be in root position; changing the inversion of these chords does not change the harmony, but it does change the function. (In music, there are exceptions to every rule.) The structural subdominant need not be a subdominant chord in root position and, indeed, need not even be a subdominant chord; supertonic harmony frequently functions as the structural subdominant.
|Music As Repetition and Variation|
|Comments on Terminology|
|Music As Language|
|This form of analysis is also based on the idea that musical expression is not based on abstract idealized principles. Music is a language - or rather, a collection of languages. It varies from age to age and culture to culture. Musical languages are not mutually intelligible. European listeners almost never understand the musical languages of Africa and India, for example. (And nowadays it seems to me that the language of European symphonic music is almost unintelligible to the vast majority of Americans.) The cadential progression [I-IV-V-I] works because it has a long history of development: people made music - composed it, performed it, listened to it - a certain way.
[ I - IV - V - I ]:
Lester Allyson Knibbs, Ph.D.
Cadential Structure ---
Unitary & Binary Structures
Linear & Periodic Structures
Modules and Modalities
Instead of seeing this progression simply as a cadence that concludes a phrase, section, movement, or entire work, cadential structure shows how this progression is the unifying framework of each tonal composition, from the smallest scale to the largest.
This form of analysis is based on the simple principle that all music consists of varied repetitions of the music that came before it and that each piece of music consists of varied repetitions of its own musical ideas. This is a fundamental principle of music, of life, of reality. (Look at your body: it is a varied repetition of the bodies that came before it, and it consists of varied repetitions of a limited number of simple functions and structures.)
|[ I - IV - V - I ]|