THE KEY-WORD HERE INTHE 4TH GENERATION DIGITAL MUSIC FOR THE MUSICAL-THEORETIC IDEAS OF THIS POST (AS FAR AS MORDEN SOFTWARE FOR MUSIC MAKING IS ) IS CHORD-SEQUENCERS AND BACKING-TRACK BUILDERS.
THE TERM SEQUENCER MEANS HERE A LOOP OR RHYTHMIC CYCLE OF ACHORD PROGRESSION (LIKE AMELODIC THEME THAT VARIES IN A MELODIC SEQUENCER).
THERE MANY GOOD SOFTWARE PROGRAMS FOR THIS LIKE CHORDBOT, NAVICHORD , ETC
We try to define tonalities in a chord progressions through the unique diatonic scale, that might be defined by the notes of three consecutive chords of the chord progression.
We give examples below and we enlarge more on this.
One of the best ways is to utilize the 24-cycle of the chords to find the local diatonic scale (defined by 3 consecutive chords) of a chord progression. Every circular arc (in the outer 12-chords cycle) of 4 consecutive chords and of 7 consecutive chords in the 24 cycle , defines a tonality and diatonic scale. So if the chord progression has many of these 4 or 7 chords, there is a tonality. The chords of diatonic scale in the 24 cycle have the next symbolism (see post 34) (x-2, X-1,x-1,X,x,X+1,x+1)=(vii,V,iii,I,vi,IV,ii). Of course the chord progression may extent to more than one tonality. And this is the advantage of the 24-cycle as it represents very common rules of modulation. Another elementary way is to define a diatonic scale from each chord as described below, by extrapolating the chord with inner transient notes (see underlined paragraph below). In any case the determination of one or more tonalities in the chord progression most often is not unique!
As we remarked from the point of view of chord progressions , a diatonic scale is a sequence of 3 consecutive major (or minor) chords in the wheel of chords by 4ths. E.g. the C major-mode diatonic scale is defined by the sequence of major chords G->C->F. They contain exactly all the notes of the scale. The A minor-mode diatonic scale is defined by the triad Em->Am->Dm. Similarly the other 7 modes like Myxolydian , Locrian etc, are defined be 3 consecutive chords that are consecutive in the wheel of 4ths but some of them are minor and some major. The same for other more general types of scales like harmonic minor etc.
For a single chord of the chord progression which is minor or major, we may extent its set of notes with the obvious extension in between them to get a diatonic triad or tetra-chord. (see post 4 and 50) ) E.g. of for the C major chord (C,E,G) two obvious extensions would be (C,D,E,F,G) or (C,D,E,F#, G). While for A minor (A,C,E) would be (A,B,C,D,E) or (A,Bb,C,D,E).
At any position of the background chord, either in root position or in any one of the 2 inversions, the transient notes may be in general and usually from the diatonic or other scales triads (see post 4) or diatonic or other scales tetra-chords (see post 50) with which we can extrapolate any of the intervals of two successive notes of the chord. Of course the different ways we can do it reflect the different diatonic or not scales that the chord belongs.Notice that in extending with a diatonic triad or tetra-chord the result may not be only a diatonic scale, but in general a scale made only from semitones and tones (see post 51) thus also melodic minor and 2nd melodic minor! In the case of course that all the chords of the chord progression belong to a single diatonic scale, then there exists an extension of the chords such that it is common to all chords of the chord progression, and is the invariant of tonality. But what we saying here is that each chord of the chord progression defines by itself at least one scale that includes notes outside the chord too! And by looking to the scales of posts 46, 50, 51, 52 we see that are plenty many scales (not modes!) that a single major, minor , diminished or augmented chord may belong
The next is a site that finds scales underlying a chord progression
http://www.scales-chords.com/chordscalefinder.php
An alternative approach to classical tonality is to define an new alternative scale (sub-scale of the 12-notes scale) from all the notes of the chords of the chord progression. We may call it the chord-progression scale, and it is an invariant of the song and is a concept of generalized tonality of the song with this chord progression.. In general such scales may not have names, it is not a tonality in the standard sense, but still they may have chords and intervals regularities on which the melody of the song may develop. The practice of improvisation within a chord progression often proves, that if say a not X belongs to a chord CH that sounds in the background, and in the improvisation a fast scaling produces a sequence of notes from a low X to 1 or 2 octaves higher X, then this can be with any scale that contains the chord CH, not necessarily one that contains more chords of the chord progression, as the in this fast scaling, all the notes are quite transient, while the note X is a stable pole! From this point of view in a improvised soloing of a chord progression, the different scales utilized might be more than the chords of the progression! Of course all these scales may have common properties.
We have discriminated between the concept o scale and mode. A sequence of notes that the total sum of intervals is an octave and all its cyclic permutations is scale. While a mode is when also we have determined a starting note. From this point of view the diatonic scale is neither major neither minor. While major or minor are modes among the other 7 modes.
One of the best ways is to utilize the 24-cycle of the chords to find the local diatonic scale (defined by 3 consecutive chords) of a chord progression. Every circular arc (in the outer 12-chords cycle) of 4 consecutive chords and of 7 consecutive chords in the 24 cycle , defines a tonality and diatonic scale. So if the chord progression has many of these 4 or 7 chords, there is a tonality. The chords of diatonic scale in the 24 cycle have the next symbolism (see post 34) (x-2, X-1,x-1,X,x,X+1,x+1)=(vii,V,iii,I,vi,IV,ii). Of course the chord progression may extent to more than one tonality. And this is the advantage of the 24-cycle as it represents very common rules of modulation. Another elementary way is to define a diatonic scale from each chord as described below, by extrapolating the chord with inner transient notes (see underlined paragraph below). In any case the determination of one or more tonalities in the chord progression most often is not unique!
As we remarked from the point of view of chord progressions , a diatonic scale is a sequence of 3 consecutive major (or minor) chords in the wheel of chords by 4ths. E.g. the C major-mode diatonic scale is defined by the sequence of major chords G->C->F. They contain exactly all the notes of the scale. The A minor-mode diatonic scale is defined by the triad Em->Am->Dm. Similarly the other 7 modes like Myxolydian , Locrian etc, are defined be 3 consecutive chords that are consecutive in the wheel of 4ths but some of them are minor and some major. The same for other more general types of scales like harmonic minor etc.
For a single chord of the chord progression which is minor or major, we may extent its set of notes with the obvious extension in between them to get a diatonic triad or tetra-chord. (see post 4 and 50) ) E.g. of for the C major chord (C,E,G) two obvious extensions would be (C,D,E,F,G) or (C,D,E,F#, G). While for A minor (A,C,E) would be (A,B,C,D,E) or (A,Bb,C,D,E).
At any position of the background chord, either in root position or in any one of the 2 inversions, the transient notes may be in general and usually from the diatonic or other scales triads (see post 4) or diatonic or other scales tetra-chords (see post 50) with which we can extrapolate any of the intervals of two successive notes of the chord. Of course the different ways we can do it reflect the different diatonic or not scales that the chord belongs.Notice that in extending with a diatonic triad or tetra-chord the result may not be only a diatonic scale, but in general a scale made only from semitones and tones (see post 51) thus also melodic minor and 2nd melodic minor! In the case of course that all the chords of the chord progression belong to a single diatonic scale, then there exists an extension of the chords such that it is common to all chords of the chord progression, and is the invariant of tonality. But what we saying here is that each chord of the chord progression defines by itself at least one scale that includes notes outside the chord too! And by looking to the scales of posts 46, 50, 51, 52 we see that are plenty many scales (not modes!) that a single major, minor , diminished or augmented chord may belong
The next is a site that finds scales underlying a chord progression
http://www.scales-chords.com/chordscalefinder.php
An alternative approach to classical tonality is to define an new alternative scale (sub-scale of the 12-notes scale) from all the notes of the chords of the chord progression. We may call it the chord-progression scale, and it is an invariant of the song and is a concept of generalized tonality of the song with this chord progression.. In general such scales may not have names, it is not a tonality in the standard sense, but still they may have chords and intervals regularities on which the melody of the song may develop. The practice of improvisation within a chord progression often proves, that if say a not X belongs to a chord CH that sounds in the background, and in the improvisation a fast scaling produces a sequence of notes from a low X to 1 or 2 octaves higher X, then this can be with any scale that contains the chord CH, not necessarily one that contains more chords of the chord progression, as the in this fast scaling, all the notes are quite transient, while the note X is a stable pole! From this point of view in a improvised soloing of a chord progression, the different scales utilized might be more than the chords of the progression! Of course all these scales may have common properties.
We have discriminated between the concept o scale and mode. A sequence of notes that the total sum of intervals is an octave and all its cyclic permutations is scale. While a mode is when also we have determined a starting note. From this point of view the diatonic scale is neither major neither minor. While major or minor are modes among the other 7 modes.
