Scruton - Aesthetics of Music 1997

I have previously made some quick notes on reading this book, but on going back over some chapters I have made some further notes upon reading Scruton - The Aesthetics of Music on the features central to triadic tonality:

A triad is a three-note chord, fundamentally built with each note possessing an interval of a third between each other creating a harmonic tonality. These notes may be varied in terms of augmentation, key, modal scale and so on to create a further three-note chord voicing. There are a number of features widely recognised as central to triadic tonality and both its use and manipulation.

The key signature employs a particular arrangement of notes based upon the tonic note, in which notes are disposed off in relation to the root note. The important function of the key signature is to bring melody and harmony close and constant relation.

The diatonic scale allows for a scale to have an ascending and descending version by designating certain tones for each key; seven tones for the major scale and nine for the melodic minor.

Non-designated tones allow any of the twelve chromatic tones belonging to the key to be added to the melodic or harmonic structure as an accidental whereas designated tones within a key have their own individual character emerging from their relation to the tonic.

Major and minor have long been a fundamental function for tonality. Every major key has a designated relative minor that utilise the same notes in their scale but begin from an alternative tonic note found three semitones below the relative major to create a new harmonic sound.

Chord relations and cadences allow for harmonic progressions and boundaries. Chord relations incorporate harmonic flow from one chord to another by progressing major intervals in relation to the tonic key. Chord cadences act as a boundary that may be either closed or act as an interruption through perfect, plagal, interrupted or imperfect cadences. These are built upon tonal tradition of what human perceives to be a perfect or imperfect ending to a chord sequence, for example chord V-I signifies a perfect ending whereas V-VI would be an interrupted climax.

Tonal music is not just driven from the notes of the diatonic scale and the harmonies implied by them, but uses these notes to create a tonal centre for where harmonies can work closely or distanced.