Each of the pitches in the diatonic scale has a "name":
tonic supertonic mediant subdominant dominant submediant subtonic
I was first introduced to tonic
, dominant
, and subdominant
in the context of "dominant
chords lead to tonic
chords, and subdominant
chords lead to dominant
chords". My own logical inference suggested that the "sub" in "subdominant" meant "less important" given its role in relation to the dominant
.
Later, I learned that mediant
and submediant
are a third above and below the tonic
, respectively, and, similarly, the supertonic
and subtonic
are a second above and below the tonic
.
That leaves me with some confusion about dominant
and subdominant
. Subdominant
could mean "one step below the dominant
", but that would be inconsistent, since the others are relative to the tonic
. Or it could mean that dominant
and subdominant
are a fifth above and below the tonic
, but this is also inconsistent: why would scale degrees 2
, 3
, and 5
be named relative to the tonic rather than 2
, 3
, and 4
?
My vague understanding is that these terms predate the diatonic scale, finding their origins in earlier (chant/modal) theories, and perhaps even as terms borrowed or adapted from ancient Greek theory.
Where do these terms come from, what were their original meanings, and what was their musical significance?
This question has its origin in the discussion in the comments of this post: Answer: What are the degrees of a pentatonic scale?
UPDATE
Wikipedia's "Submediant" entry contains this interesting tidbit:
In French and Italian, a conception with two centres, subtonic (sous-tonique, sotto-tonica) and supertonic (sustonique, sopra-tonica) on both sides of the tonic, subdominant (sous-dominante, sotto-dominante) and "superdominant" (sus-dominante, sopra-dominante) on both sides of the dominant – and the mediant left alone between the two.
The English/German terminology was used in constructing the present question, in which the super/sub designations relate to position relative to the tonic. But the French/Italian terminology supports the intuition that "subdominant" should mean "below the dominant" (see first paragraph above).
subtonic tonic supertonic mediant subdominant dominant superdominant