It Could Happen To You - Automatic Chord Sequence Analyser System

Automatic Chord Sequence Analyser System

Title: It Could Happen To You
Stated key: of Ab 4/4
Chord sequence: (use spaces or newlines to separate chords)

| Clear | Analyse dim/aug chords Remove duplicate chords Show additional data| Jazz standards library | Examples |

Listen in MIDI Main key: Ab (confidence 140/130, minority 11%)

Degree:IIImIIVIIIVIIVIVmIIIIVImIIIImVbIIIIImIIVIIIVIIVIVmIVIIImVII
Source:AbBbm7AbDbC7F7DbDbmAbC7Fm7Bb7Bbm7Eb7A7AbBbm7AbDbC7F7DbDbmAbF7Bbm7Eb7AbAb
Key:AbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAbAb
Move:+1-1+2.5-0.5+2.5-20-2.5+2+2.5+2.50+2.5+3-0.5+1-1+2.5-0.5+2.5-20-2.5-1.5+2.5+2.5+2.50
Common:Ab,C,EbBb,Db,F,AbAb,C,EbDb,F,AbC,E,G,BbF,A,C,EbDb,F,AbDb,E,AbAb,C,EbC,E,G,BbF,Ab,C,EbBb,D,F,AbBb,Db,F,AbEb,G,Bb,DbA,Db,E,GAb,C,EbBb,Db,F,AbAb,C,EbDb,F,AbC,E,G,BbF,A,C,EbDb,F,AbDb,E,AbAb,C,EbF,A,C,EbBb,Db,F,AbEb,G,Bb,DbAb,C,EbAb,C,Eb
N:1234567891011121314151617181920212223242526272829

Statistics of detected keys:
KeyConfidenceGuessesFixed keyChordsMinority
Ab (Fm)
140
19 (66%)
29 (100%)
9 (31%)
1 (11%)
Main key
Db (Bbm)
130
17 (59%)
0 (0%)
8 (28%)
4 (50%)
Second possible key
Eb
113
10 (34%)
0 (0%)
2 (7%)
0 (0%)
Gb
96
8 (28%)
0 (0%)
0 (0%)
0 (0%)
Bb
87
3 (10%)
0 (0%)
1 (3%)
0 (0%)
H
83
2 (7%)
0 (0%)
0 (0%)
0 (0%)
E (Dbm)
78
2 (7%)
0 (0%)
2 (7%)
2 (100%)
F
76
3 (10%)
0 (0%)
3 (10%)
0 (0%)
C
61
0 (0%)
0 (0%)
3 (10%)
0 (0%)
A
58
2 (7%)
0 (0%)
1 (3%)
0 (0%)
G
42
0 (0%)
0 (0%)
0 (0%)
0 (0%)
D
37
1 (3%)
0 (0%)
0 (0%)
0 (0%)


Key - shows the key detected for the position. Algoritm tries to detect minor keys based on occurence of minor tonic keys in the part.

Pink chord background - shows chords, that do not interact with the previous line and form new key

Degree - shows the degree of chord over the detected key

Guesses - shows the possible keys in the position, taking previous chords into account. Guesses are always major. If there is more then one possibility, algorithm will not show it in the Key row. Those selected for ultimate keys are green

Local - shows all possible keys for the chord, without taking previous chords into account.

SLocal - shows most probable keys for the position, considering several chords before and after it

Minority - probability of the current key being minor (calculated based on surrounding chords statistic)

Move - shows how many whole tones the key jumps to the next chord:
0Same base key. e.g. C -> Cm
+0.5 or -0.5Chromatic movement. e.g. C -> C#dim
+1,5 or +2 or -1,5 or -2Mediant movement. e.g. Em -> Ab
+2.5Classic resolving V -> I. e.g. G -> C
-2.5Rock resolving IV -> I. e.g. F -> C
+3Tritone movement. e.g. H -> F
1, 1.5 and 2 jumps are not colored

KMove - shows how many whole tones the key jumps to the next key

Common - shows notes of the current chord, highlighting notes, that are common with the next chord

MDiss - shows notes of the current chord, which dissonate with diatonic of the Main key

Diss - shows notes of the current chord, which dissonate with diatonic of the current key

Mouse over the table to see additional information


The algorithm knows Bb and H notes. B is interpreted as H, not Bb!

Example: F-7 Bb-7 Eb7 Abmaj7 Dbmaj7 D-7 G7 Cmaj7 C-7 F-7 Bb7 Ebmaj7 Abmaj7 A-7 D7 Gmaj7 A-7 D7 Gmaj7 F#-7 H7 Emaj7 F-7 Bb-7 Eb7 Abmaj7 Dbmaj7 Db-6 C-7 Hdim Bb-7 Eb7 Abmaj7

You can use following chords: m (minor), - (dorian), 7 (sept), maj7 (major 7), dim (diminished), m7b5 (half diminished), aug or + (augmented), b9 (contains b9)

If you want to use sixth notes, use chord inversions instead. e.g. Am7 instead of C6, or Hm7b5 instead of D-6

2011 Copyright by Alexey Arkhipenko. Please feel free to write me feedback: rualark at google mail (gmail.com)

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