[Smt-talk] Subdominant versus Predominant

[Ninov, Dimitar N]

"Subdominant. Name given by Rameau to the fourth note of the key, which therefore is at the same descending interval from the tonic as the dominant is ascending."

Exactly: "...the same descending interval from the tonic as the dominant is ascending!" Now compare to my statement again: The term "subdominant" suggests that the IV chord is located a fifth below the tonal center, and that it is a "lower dominant". Any discrepancies?

Historically supported? Absolutely yes - but not in terms of chord which connects to the dominant; rather, in terms of a chord which stands a fifth below the tonic and is named "lower dominant" to be distinguished from the "upper dominant".

What is the most striking feature in the I-IV-V-I progression? The fact that from the state of stability (T) we leap into a state of instability (S) which then increases (D) to bring us back into the realm of tonic (T). In this progression the strong connections are I-IV and V-I, because they embody the departure from the stability of the center (I-IV), and the return to the center from a most unstable area (V-I). 

In contrast, the connection IV-V is not so impressive, because it does not link two polar states (stability and instability) but simply represents a process of increasing of the instability by one degree. In addition, the I-IV connection is literally executed through a leap of a perfect fourth, which is an impressive start, while the IV-V connection involves a stepwise motion in the bass.

Since I-IV is acoustically and functionally more impressive than IV-V in a I-IV-V-I progression, the question "What follows the tonic?" is more relevant in identifying the harmonic function of IV than the question "What precedes the dominant?" The former question is an equivalent to a more important question, namely "How do we leave the state of stability?". On the other hand, "What precedes the dominant?" is an equivalent of the question "What is the lower degree of instability?" which does not seem as important.

According the the logic explained above, the arrangement T-S-D-T makes perfect sense, but T-PD-D-T does not, for it answers the question "What is the lower state of instability?" instead of answering "How do we leave the state of stability?". This argument, paired with the fact that harmonic functions refer to the tonal center, in my view renders the label "PD" both superfluous and superficial.

Thank you,

Dimitar

Dr. Dimitar Ninov
Texas State University
dn16 at txstate.edu

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