)After observing many squirrels and their behavior (and studying many tunes by Gershwin and Porter, et al) I have come to develop my "Harmonic Squirrel Theory" and share it with the world.
Thesis: Squirrels can teach us a lot about songwriting (and vise-versa).
Glossary of Terms:
Home key - The key center that generally starts and ends a song...the key of the tune.
Secondary key - A temporary key within the tune that is used for tonal contrast
Cadence - I use this term not to just mean the end of a piece or a section or even a phrase. They also include any preparation of a resolution to either a home key or the secondary key - classic "up a forth" root movement, although in jazz you can find dominant subs to accomplish the same thing.
Home Tree - Where a particular squirrel's starting position is. The squirrel may have a nest here.
Secondary Tree - A temporary tree that is any tree other than the home tree. Squirrels find safety in trees.
Observation of Tonal Behavior in Songs from the "Great American Songbook":
1) Many phrases are comprised of classic "antecedent/consequent" structure with the former solidifying the tonality by means of ii V I cadence (or its numerous variations involving substitutions)
Example A: Moonlight in Vermont - Antecedent phrase (Lyrics "Pennies from a Stream...") I - vi - ii - bIIMaj7 - I
Example B: But Not for Me (Gershwin) - Antecedent phrase (Lyrics "They're writing songs of love...") V7(b9) - I - vi - ii7 - V9(b9)
Consequent phrases utilize cadence in new temporary key via similar ii V I cadence.
Example C: But Not for Me - Consequent phrase (Lyrics: "A lucky star's above...")
I - vi - iii - V7/ii - V7/V - V7 - V7/IV - IV(Maj7)
2) Contrasting key in the second part of the chorus is accomplished via ii V I progression (with or without classic substitutions) in numerous other keys
Example: Moonlight in Vermont (Lyrics "Telephone lines sing down the highway") ii - V - I in the major mediant (twice), followed by a ii - V - I in the subdominant (twice) and the turn-around back to the tonic via ii - V - I.
(Many fake or real book versions of this tune use tri-tone subs in just about all the above cadences.
Summary of above points: The examples above are typical and numerous other examples exist in the popular literature of the 30s, 40s, 50s and 60s.
Cadences establish the original tonal center, but direct modulations via similar cadences to other key areas (often remote) are used for contrast. However, the original key can be accessed at any time by a sudden three-point cadence to a satisfying close back in the tonal "home turf"
Observation of Squirrels in the Park:
1) Squirrels always relate their movement on the ground in relationship to the location of trees. (Because trees = safety)
2) Squirrels typically move on the ground in the following pattern: Move by three jumps - Stop (twitch-twitch with the tail) - Turn - Move with three jumps - Stop (twitch-twitch), etc.
3) If there is a perceived threat (e.g. I walk near them) the squirrel goes for a tree (whereupon they go up about two meters, stop behind the tree from me and wait, or they may peer around the tree to assess my intent)
4) Squirrels rarely venture so far away from a tree that they can't execute #3 above by doing #2 above.
(Exception is in street areas where the trees are far apart and have to run like hell across the street. I think that they often STOP and switch directions because they now perceive a car coming and the closest tree is behind them...see #1)
So to gather food, a squirrel - like music - has to leave the home tree of the original tonality. Otherwise they would surely die of starvation. So the squirrel will sit and the bottom of the tree trunk and execute a food gathering pattern...
Three jumps on the ground...stop (two twitches of the tail)...look around "where is the tree from here? where is ANY tree from here?"...
(Three "jumps" in the musical phrase is ii V I. End of antecedent phrase.)
"Is there a threat?" No. So three new jumps in the new direction...stop (twitch-twitch)
(Three "jumps" in the consequent phrase...ii V I in the temporary new key area)
"Is there a threat?" No. Execute same move..."Uh-Oh! We are getting further away from the tree."
(ii V I in yet another key area.)
"Is there a threat?" Yes! A poodle is coming!"
"Is the home tree closest or is there a secondary tree closest?" Home tree is closest. Point nose toward home tree. Three jumps and up the tree you go.
(The section is coming to a close. Should I close in the home key or secondary key? Three "jumps" back via direct modulation and you are back home, or you can close the section out in a new temporary key.
General rules for squirrels and musical phrases:
A) Prep your movements toward areas of repose using the most economical of movements.
B) Add substitutions or other chromatic movements (secondary dominants) to "fake out" your observer and keep them slightly off-guard in case you need to ditch out.
C) Always select new directions tonally in your phrases in order to maximize nut gathering potential (variety and contrast)
D) Never get too far away from safety so that you cannot return immediately by direct three-step cadential harmonic movement
E) You can seek the safety of a secondary tree (or key) but you'll eventually need to get back home before the sun goes down.
F) Not having a clear phrase strategy will get you run over by the Buick of Indecision
