17.2: Tonicization
17.2 Tonicization
In this chapter and the next, we will study tonicization , which means treating a chord other than the II chord like a tonic by approaching it with its dominant. In diatonic harmony, the VV chord (the dominant) resolves to the II chord (the tonic). A secondary dominant is a major triad or dominant seventh chord that resolves to (or tonicizes ) a chord other than the II chord.
Sing the bass line of the example above and notice that a secondary chord, through its chromaticism, intensifies the drive to the next chord.
Principle 17.2.2. Secondary Dominants.
The Roman numeral after the slash is the chord being tonicized by the VV chord before the slash.
You may find that you want to analyze the DFD7/F♯ in the example above as a IIII56instead of a VVV56/V (which we pronounce as “VV56 of VV”), and the EGE7/G♯ as a IIIIII56instead of VviV56/vi (“VV56 of vivi”). Notice, however, that a iiii chord is typically minor in a major key and diminished in a minor key (iiii∘), making uppercase IIII a chromatic harmony for which the proper label is VVV/V.
While labeling DD7 as IIII7 in C major makes the root clear, it does not communicate the function of the DD7, which is to progress to a G major chord (the VV chord, or the dominant in C major).
Also, notice that viivii∘ is not tonicized with its secondary dominant in the example above. Listen to the following example to understand why diminished chords such as viivii∘ and iiii∘ in minor are not tonicized.