Multi-tonic systems?

[petepachio]

Ive heard the phrase many times..but i dont know what it means or involves.Anybody care to explain? or is there a book on this type of system? thanks

[bluewaterpig]

Multi-tonic systems are basically a series of different key centers that split up an octave evenly. The importance of this is that when the key centers are evenly split within an octave, it makes each new key center totally separate from the original key. In other words, when the new key change occurs, the previous key has absolutely no tonal relevance.

For example, if a tune is in F, a very common modulation is to move to Bb (let's say using Cm7 and F7). When this happens, you can still hear the home key of F. But in a multi-tonic system where the key centers equally divide an octave, this doesn't happen. The equal intervals between the keys makes it hard to hear the original key.


A multi-tonic system is most commonly a section of a tune, like the bridge.

An example of a MTS is in the bridge of 'Have You Met Miss Jones'. The B section modulates through 3 different keys: Bb, Gb, and D.

The important thing here is that each of those keys are a major 3rd away from one another. The octave is evenly divided into 3 parts. The order of modulations is not exclusive, meaning you don't have to go in a specific order, and you can also repeat keys (the bridge of Miss Jones moves to Gb twice).

When we move to Gb from Bb, the listener cannot trace the tonal center back to Bb, and the same thing happens when we go to D. They are totally exclusive from one another and you cannot hear the previous key after the modulation.

There are a limited number of MTS's available because the octave can only be equally split in so many ways. Here's a list of the different MTS's and the interval that's used to achieve each one:

MTS 6 = Major 2nds
MTS 4 = Minor 3rds
MTS 3 = Major 3rds
MTS 2 = Tritones

MTS's can be found in a bunch of different tunes. It's a really great harmonic concept to use in composition.

[eddy b.]

Multi tonics are derived from the equal division of the 12 note chromatic octave. Divide the 12 note chromatic octave by 4 and the anwer is 3. 3 half step equals a minor 3rd. starting on C. the equal division would be C Eb Gb A. Make each of these notes a new I chord then add their respective V chords. Coltrane divided the 12 note chromatic octave by 3 which equals 4 half steps. 4 half steps equals a Major 3rd. starting on C the equal division of the Octave is C E G#. Make each of these notes a I chord add their V chords and that is how the harmony to Giant Steps etc. is created. It is a deep subject...check out Slonimskys Thesaurus of Scales and Melodic Patterns to have your mind properly blown.