Ramsay
"The subdominant, or lowest chord in the key - F, A, C, is the natural product of the first combination of the three primary ratios (2, 3, 5). Their second combination develops the tonic or middle chord C, E, G. The third combination develops the dominant or highest chord G, B, D.
| first combination of the three primary ratios | F | Mj 3rd | A | Mn 3rd | C | Subdominant |
| second combination of the three primary ratios | C | Mj 3rd | E | Mn 3rd | G | Tonic |
| third combination of the three primary ratios | G | Mj 3rd | B | Mn 3rd | D | Dominant |
from [Scientific Basis and Build of Music, page 17]
See Also
Ramsay - The Great Chord of Chords, the Three-in-One17
second combination of the three primary ratios
third combination of the three primary ratios
three primary ratios