@gugliel said:
RK, Here is Jadassohn's way of putting your rule:
The most universal medium for modulating easily and rapidly from one key into another is the [i]diminished chord of the seventh[/i]. It may enter freely anywhere, without preparation of the seventh. It admits of very various resolutions and progressions in major and minor, and by means of the enharmonic change of one or several or all of its tones it can pass over to the most diverse keys.
ok here's another idea. try using the diminished 7th as an underlying theory in and of itself rather than an isolated modulation method. in other words, begin by taking the notes C, Eb, F#, and A (a diminished chord) and using this as the basis for all chordal movement. play a C chord, either minor or major then move a third up to Eb or down to A (again, either minor or major chords are fine), or equidistantly up or down to the tritone, F#. So the summary of this theory is that you work in basic triads (no coloration notes like 7, 9, 11 or 13) and constantly move either up or down by third or tritone; just never in conventional I-V structures. either major or minor triads are okay at any time, and when considering the movement by third, either a major or minor third is fine, i.e. C to Eb is just as good as C to E natural.
well, obviously this wouldn't have seemed new to Wagner, but it is a fundamental basic in writing for film because cadences can be avoided in a way that propels cinematic motion. then when a hit or cadence is actually desired, it sounds natural and can be done quickly at really almost any point. As you play with this you will notice an effective solution to move by step (C-F#-D rather than just C-D) which alleviates voice leading problems if doing a lot of stepwise writing. Additionally chromatic movement can easily be achieved as in C-Eb-B (up a minor 3rd and down a major 3rd), and both of these methods serve to modulate into the structure of yet another diminished chord.
Taking this into a more advanced realm, consider that there are only three possible diminished chords, and that those can only be transposed (or inverted depending on how you want to look at it) four times before the chord replicates itself. great, big deal; fodder for the nerd in all of us. but these aren't the only place where limited inversion and transposability occur in music. have a look at Olivier Messiaen's modes of limited transposition and then apply them to this diminished structure. for the esoteric theorist, this represents a direct empirically developmental link between 19th and 20th century music, instead of a anarchistic break between the two as many have attempted to suggest.