CN103093748B - Method of automatically matching chord for known melody - Google Patents

Abstract

The invention discloses a method of automatically matching a chord for a known melody. The method comprises the steps: endowing weighted values for notes, calculating the weighted value occupied by each tone with a bar as a unit, calculating the harmonious degree of each bar, S1, S2, S3, S4, S5 and S6, respectively calculating the prepared chord of each bar, permuting and combining chords, in the connection of each group of chords according to a classical harmony theory basis, calculating sound orientation intensity degrees of two adjacent chords, finally obtaining the total value of orientation intensity degrees of connection of each group of chords, and using a maximal group or any group of maximal values to match the chord. The method transforms the natural law of music into a digital law, carries out calculation according to a certain process, and finally obtains the matched chord. Therefore, a professional limit and labor intensity of manually matching the chord are greatly reduced, and modification and revising work in musical creation is convenient.

Description

A kind of method of giving known melody Auto-matching chord

Technical field

The present invention relates to a kind of computer programs process and identify the method for the tone mark of known beat music, specifically refer to a kind of method to known melody Auto-matching chord.

Background technology

Note: in numbered musical notation, the height of record tone and the symbol of length, be called note.And be used for the symbol of the height that represents these sounds, be to serve as a mark with seven arabic numeral, their literary style is: 1234567 pronunciations are: do re mi fa so la si(carrys out meter Fa Suolaxi more).Note is closely connected with pitch, the note that neither one voiceless sound is high.

Pitch: the numeric character of note just represents different pitches as 1234567, can understand very intuitively note and pitch on fingerboard, broadly says and in music, altogether just has 7 notes.

Adjust: plain saying is exactly 1(do in head adjusts) absolute position of sound, (such as 1=A is that tone mark is A, expression is sung this sound of A to make do), in music, one have 12 tone marks:

The length of note: the note in music except have height exceptionally, certainly also to represent length point, quote a basic music terms----bat here.

Music beat refers to the combination rule of strong beat and weak beat, specifically refers to the note total length of each trifle in music score, 2/4,3/4,4/4,6/8 common bat, and the length of every trifle is fixed, and in the time that the beat of first melody is composition, fixes, and can not change.One first melody can be combined and be formed by several beat, and its rule is as follows: 2/4 claps: 2/4 to clap be that 4 dieresis are a bat, and every trifle 2 is clapped, and can have 24 dieresis, strong, a little less than; 3/4 clap: 3/4 clap be that 4 dieresis are a bat, every trifle 3 is clapped, and can have 34 dieresis, strong, weak, a little less than; 4/4 claps: 4/4 to clap be that 4 dieresis are a bat, and every trifle 4 is clapped, and can have 44 dieresis, strong, weak, inferior strong, a little less than; 6/8 clap: 6/8 clap be that 8 dieresis are a bat, every trifle 6 is clapped, and can have 68 dieresis, strong, weak, a little less than; Inferior strong, weak, a little less than.

Time signature is a mark, writes on the place (left end of the first row stave, follows after clef, if there is tone mark, order is clef → tone mark → time signature) that melody starts.Denominator represents the basic duration of bat, that is to say with several dieresis as a bat, in point every trifle of subrepresentation, has several bats.For example: 2/4 represents taking crotchet as a bat, and every trifle has two bats; 3/4 represents taking crotchet as a bat, and every trifle has triple time; 3/8 represents taking quaver as a bat, and every trifle has triple time.The denominator part of time signature only has 2,4,8 three kind, that is to say the basic duration with minim, crotchet and quaver as bat.Why time signature writes component number, be because in staff using whole note as integer, the fundamental unit cut apart of instantaneous value treats.The mark of whole note is C, establishes C and equals 1, and the duration of minim is 1/2 naturally, and in the time having two bats (two minims) in a trifle, its duration is 1/2+1/2, draws the time signature 2/2 of fractional form; In the time having triple time (three minims) in a trifle, duration is 1/2+1/2+1/2, and the time signature of fractional form is 3/2; As a same reason, the duration of crotchet is 1/4, and when every trifle has two bats (two crotchets), time signature is written as 2/4, has triple time (three quarter step symbols) to write and do 3/4, and the rest may be inferred.

Music is always hocketed by strong beat and weak beat, this alternately can not be disorderly and unsystematic, arrange arbitrarily, organize a trifle but form minimum beat according to certain rule, then move in circles based on this.Such as, in the time only having a weak beat between two strong beats, being called " two beat ", 2/4 beat is exactly this type; In the time having two weak beats between two strong beats, be called " triple time ", resemble 3/4 and 3/8; Between two strong beats, there are three weak beats to claim " four beat ", commonly 4/4.Between two trifles, separate with " bar line ".Bar line is a fine rule vertical with stave, upper top five lines, under connect a line, just in time by stave cut off, no matter upper and lower ledger line leaves stave How far, bar line all can not exceed outside stave.Last trifle of works is drawn two bar lines, and of the right side is thick, represents the end of works or a paragraph, and bar line that bat below must be strong beat, and each trifle only has a strong beat, and all the other are weak beat.

Bat is the key concept that represents note length, refer to the combination rule of strong beat and weak beat, the length that represents music need to have a relatively-stationary concept of time, in numbered musical notation, note is divided into whole note, minim, crotchet, semiquaver, demisemiquaver etc., the most important thing is crotchet in these note the insides, it is a basic reference tolerance length, be that crotchet is a bat, here a concept of clapping is a relative time linear module, one length of clapping does not limit, it can be 1 second, also it can be 2 seconds or half second, if a bat is the length of a second, two bats are exactly two seconds so, one bat is decided to be half second, and two bats are exactly the length of one second, once a bat on this basis is decided, longer or short than a bat so symbol is just relatively easy, in the time that the beat of first melody is composition, fixes, and generally can not change midway.

Note is divided as follows:

Syncopation: syncopation be melody in the middle of carrying out, due to the needs of music, there is variation in strong beat and the weak beat of note, and occur tempo variation.Such as: sound is when the weak beat, and be extended to the place of forte below, broken normal strong and weak rule, original strong or weak relation has been put upside down, this sound shape is " syncopation ", and due to longer than front and back note duration, the stress of cutting rhythm must be on syncopation.

Diatonic scale: scale is exactly a cross-talk of arranging in turn with whole tone, semitone and other intervals, basic scale is that C tunes up scale, plays the white key of Shi Quanyong on piano, is followed successively by C D E F G A B.

Twelve-tone equal temperament: twelve-tone equal temperament by the interval of octave by frequency equal proportion be divided into ten halves, it is minor second that each equal portions is called a semitone.

Musical alphabet: musical alphabet is exactly the title of pitch, i.e. C, D, E, F, G, A, B, the relation of musical alphabet and pitch is absolute; The musical alphabet of the pitch of every high or low octave is the same.

Clap position: the position of each bat in beat, we add that with letter numeral represents.The kind of letter representation bat, which claps numeral, and such as R1 represents the first count in 42 bats, P3 represents the bat of the 3rd in 44 bats.

Interior bat position: represent a bat to be divided into again 4 points, the position of every portion, we represent with alphabetical J1-J4, such as J3 represents the 3rd position of current bat.

Note position: represent concrete position with clapping position+interior bats position, such as Q2J3, Q2 represents in 42 bats that the 2nd claps J3 and represent the 3rd 16 dieresis, and the comprehensive meaning is the 3rd 16 dieresis in the 2nd bat.

Conventional common chords, taking C natural major as example:

Summary of the invention

The object of the present invention is to provide a kind of method to known melody Auto-matching chord, be used to single melody of one section of known tone mark, tonality, time signature to mix the chord of one group of harmony.

Object of the present invention is achieved through the following technical solutions:

A method of giving known melody Auto-matching chord, comprises the following steps:

(A) in any one section of melody, give each clap position weighted value by any one trifle of this melody according to its fixing beat, in each trifle, each weighted value summation of clapping position is 100; And taking trifle as unit, calculate respectively each sound in the shared weighted value of this trifle;

(B) calculate harmonious degree S1, S2, S3, S4, S5, the S6 of six grades of chords of each trifle first order to the;

(C) calculate respectively the preparation chord of each trifle;

(D) taking trifle as unit, to prepare chord as material, these chords are carried out to permutation and combination, show that some groups of chords of this section of melody connect;

(E) then according to classic harmony theoretical foundation, during each group chord is connected, every two adjacent chords carry out the calculating of sound tendentiousness degree of strength, finally draw the total value of the tendentiousness degree of strength that every group of chord connect, any one group that gets in maximum one group or maximal value is coupling chord.

The present invention gives weighted value to the note of any trifle according to the strong or weak relation rule in music beat, then calculates its comparatively suitable chord according to its each note weighted value, makes dull melody to become excellent melody by Auto-matching; The present invention converts the natural law of music to digital rule rate, and calculate according to certain process, finally obtain the chord of its coupling, so, greatly reduce professional threshold and the labour intensity of artificial coupling chord, and can be so that amendment, the revision in musical composition.

In described step (A), comprise the following steps:

(A1) beat of described melody is any one in 2/4 bat, 3/4 bat, 4/4 bat or 6/8 bat, and wherein the ratio of the 2/4 bat position weighted value of clapping is R1:R2, and R1>R2; The ratio of the 3/4 bat position weighted value of clapping is T1:T2:T3, and T1>T2>T3, T2+T3>T1; The ratio of the 4/4 bat position weighted value of clapping is P1:P2:P3:P4, and P1>P2>P4, P1+P2>P3+P4, P2+P3>P1, P1>P3; The 6/8 bat position weighted value of clapping is assigned as two parts, and its ratio is identical with 2/4 rule of clapping, and wherein the bat position weighted value of each part distributes rule identical with 3/4 rule of clapping.Specifically, the distribution rule of weighted value is to give according to the strong and weak rule of music beat, and wherein, the 2/4 strong and weak rule of clapping, is respectively often quaver, according to the strong and weak rule R1>R2 of rhythm, the 3/4 strong and weak rule of clapping is by force-weak-a little less than, according to the strong and weak rule T1>T2>T3 of rhythm, according to the strong and weak rule T2+T3>T1 of cutting rhythm, the 4/4 strong and weak rule relation of clapping be strong-weak-inferior strong-a little less than, according to the strong and weak rule P1>P2 of rhythm >P4, P1+P2>P3+P4, according to the strong and weak rule P2+P3>P1 of cutting rhythm, clap strong and weak rule P1>P3 by 4/4, P2>P4, the effect of this step is to determine to clap position weighted value and interior ranking weighted value, so that by pitch, the duration of a sound and rhythm power change into a kind of numerical value that can calculate, the principle of this step: according to the strong and weak rule of music beat itself, and the strong and weak rule principle of cutting rhythm, then draw following ratio range: because this is the data of one group of interlock, so ratio upper limit lower limit is all the definition for first count span.

4/4 claps strong and weak rule:

The 3/4 strong and weak rule of clapping:

The 2/4 strong and weak rule of clapping:

If due to 4/2 bat duration is expanded and being twice, its strong and weak proportionate relationship and 4/4 is clapped consistent, thus R1=P1+P2, R2=P3+P4;

(A2) each independent bat is divided in 4 parts and claps position, weighted value is given respectively in each interior bat position, and the weighted value sum of clapping position in each independent bat in 4 equals the weighted value of this independent bat;

In described single bat, the ratio of clapping the weighted value of position in it is J1:J2:J3:J4, and J1>J2>J4, J1+J2>J3+J4, J2+J3>J1, J1>J3;

The effect of this step: be for less segmentation beat unit, 4/4 to pat a strong and weak rule consistent with it because clap position in clapping, so span is as follows:

(A3) melody pitch mapping, is all mapped to the perfect pitch value of all notes that occur in melody in same octave;

(A4) contraposition of melody duration is decomposed, and the sound that each is greater than 16 dieresis, splits into the set that least unit is the sound of 16 dieresis, calculates the weighted value of each 16 dieresis according to the shared bat position of each sound and interior bat position ratio;

(A5) weighted value of mapping pitch is calculated, and is unit by trifle, calculates respectively the shared weighted value of the each sound of this trifle.

Described step (C) comprises the following steps:

(C1) select a maximal value in S1, S2, S3, S4, S5, S6;

(C2) maximal value of selecting with step (C1), calculates respectively S1, S2, S3, S4, S5, S6 and this peaked ratio;

(C3) whether >=80% ratio that to judge step (C2), in the time of ratio >=80%, classify this kind of chord as preparation chord.

Specifically, in the present invention, prepare in the computation process of chord, first be that the note picnometer of various significance levels in each trifle is calculated, obtain the harmonious value of six kinds of value of series strings of every trifle, but in these chords, some is ungraceful, do not meet musical rule, therefore, according to the rule of music, adopt in the ratio of each value of series string and maximal value chord, whether >=80% be condition, picks out the chord of suitable grade from six grades of chords, inapplicable chord is removed, for next step calculating judges the support of having made raw data.

Described step (E) comprises the following steps:

(E 1) defines chord intensity weighted value F, MF, M, the P of its variation according to the Changing Pattern of adjacent two trifle chord progression, and F, MF, M, P form arithmetic progression, and the related table of its formation is as follows:

in this form, each strong and weak numerical value represents that respectively chord progression taking its top is as current trifle, with taking its left side chord progression be after the variation tendency of a trifle;

(E2) calculate respectively the chord intensity weighted value summation that every group of chord connects;

(E3), in the result calculating, select numerical value maximum one group or wherein any one group, its corresponding chord is the chord of coupling.

Specifically, chord carries out the scope that intensity comprises for classical music theoretical foundation.In theory, chords at different levels are divided into three different groups: T(master) S(subordinate) D(genus)

Wherein III level is master function, contains the function of tonic chord and the function of dominant simultaneously; Wherein VI level is the main lower function of dominant, contains the function of tonic chord and the lower function of dominant simultaneously; VII level, owing to being the chord that is discord, seldom occurs, so this algorithm does not comprise this chord in conventional song.

The expulsive force of music is by these three groups of harmony cycle alternations, produce by be stabilized to unstable to more unstable again to stable acoustics, people therefrom obtain acoustically satisfied.An independent chord does not have the concept that chord carries out, and only has in the time that a chord proceeds to next chord, just can show tendentiousness acoustically, the degree of strength that namely chord carries out; According to the chord transition relation of music, be set for strong, inferior strong, in, a little less than, give chord intensity weighted value F, MF, M, P by these four strong or weak relations respectively, then calculate the summation of chord weighted value in whole melody, finally calculate qualified chord, underproof chord group is removed, met the natural law of music.

Described step (D) must meet the following conditions: (D1), in the time that this melody is large tune melody, its first trifle and last trifle are I level, and in the time that this melody is ditty melody, its first trifle and last trifle are VI level; (D2) the chord difference of arbitrary neighborhood two trifles.Further, in melody, the first trifle and last trifle chord are necessary for tonic chord, and (the large tonic chord of adjusting is I level, ditty is VI level) this is changeless, therefore, the relation that can take pressure to give, according to the characteristic of its tonality, the ditty that will be in harmonious proportion greatly distinguishes, when large tune melody, its first trifle and last trifle are I level, in the time that this melody is ditty melody, its first trifle and last trifle are VI level, simultaneously, for fear of the situation that occurs between continuous two trifles that chord acoustics is stagnated, can not make the chord of adjacent two trifles identical, also meet the natural law, solve music and there is no expulsive force problem, there is universal applicability.

The present invention compared with prior art, has following advantage and beneficial effect:

A kind of method of giving known melody Auto-matching chord of 1 the present invention, give weighted value to the note of any trifle according to the strong or weak relation rule in music beat, then calculate its comparatively suitable chord according to its each note weighted value, make dull melody to become excellent melody by Auto-matching; The present invention converts the natural law of music to digital rule rate, and calculate according to certain process, finally obtain the chord of its coupling, so, greatly reduce professional threshold and the labour intensity of artificial coupling chord, and can be so that amendment, the revision in musical composition;

A kind of method of giving known melody Auto-matching chord of 2 the present invention, in the computation process of preparation chord, first be that the note picnometer of various significance levels in each trifle is calculated, obtain the chord value of six kinds of grades of every trifle, but in these chords, some is ungraceful, do not meet musical rule, therefore, according to the rule of music, adopt in the ratio of each grade chord and maximum chord value, whether >=80% be condition, from six grades of chords, pick out the chord of suitable grade, inapplicable chord is removed, for next step calculating judges the support of having made raw data,

A kind of method of giving known melody Auto-matching chord of 3 the present invention, according to the characteristic of its tonality, the ditty that will be in harmonious proportion greatly distinguishes, when large tune melody, its first trifle and last trifle are I level, in the time that this melody is ditty melody, its first trifle and last trifle are VI level, simultaneously, for fear of the situation that occurs between continuous two trifles that chord acoustics is stagnated, can not make the chord value of adjacent two trifles identical, also meet the natural law, solve music and do not had propulsive problem, there is universal applicability.

Embodiment

Below in conjunction with embodiment, the present invention is described in further detail, but embodiments of the present invention are not limited to this.

Embodiment

A kind of method of giving known melody Auto-matching chord of the present invention, known tone mark: 1=C, time signature: 4/4, tonality: adjust greatly | 1235 | 6---| 7-5-| ---||

For this melody, carry out successively according to following steps:

(A1) give weighted value according to 4/4 bat, its ratio of clapping position weighted value is P1:P2:P3:P4, and P1>P2>P4, P1+P2>P3+P4, P2+P3>P1, P1>P3;

(A2) each independent bat is divided in 4 parts and claps position, weighted value is given respectively in each interior bat position, and the weighted value sum of clapping position in each independent bat in 4 equals the weighted value of this independent bat;

(A3): the high pitch of last trifle 1 is mapped to middle pitch 1. as follows:

| 1 2 3 5 |6 - - - |7 - 5 - | 1 - - - |

(A4): long decomposes, and result is as follows:

| 1111 2222 3333 5555 | 6666 6666 6666 6666 |

| 6666 6666 7777 5555 | 1111 1111 1111 1111 ||

(A5): add up the each note weighted value of each trifle:

The first trifle: the weighted value that note 1 occupies equals its long decompose after the shared weighted value of every part and:

P1J1+P1J2+P1J3+P1J4 (wherein ranking in the J representative of position is clapped in P representative)

=(100*0.4*0.4)+(100*0.4*0.2)+(100*0.4*0.3)+(100*0.4*0.1)=40

1 weighted value of occupying in the first trifle is 40;

The weighted value that note 2 occupies equals P2J1+P2J2+P2J3+P2J4

=(100*0.2*0.4)+(100*0.2*0.2)+(100*0.2*0.3)+(100*0.2*0.1)=20；

The weighted value that note 3 occupies equals P3J1+P3J2+P3J3+P3J4

=(100*0.3*0.4)+(100*0.3*0.2)+(100*0.3*0.3)+(100*0.3*0.1)=30；

The weighted value that note 5 occupies equals P4J1+P4J2+P4J3+P4J4

=(100*0.1*0.4)+(100*0.1*0.2)+(100*0.1*0.3)+(100*0.1*0.1)=10

Therefore the weighted value of all notes of the first trifle is as follows:

Draw the second, the three by this algorithm, the weighted value table of the each sound of the 4th trifle:

(B) calculate harmonious degree S1, S2, S3, S4, S5, the S6 of six grades of chords of each trifle I level to the; Obtain so-called harmonious degree and refer to a chord harmonious degree in sense of hearing in this trifle, number and the significance level of specifically being occupied in the melody of this trifle by three sounds that form this chord are determined, such as: the formation of I level chord be 135 so these three sounds in the first trifle, all occurred, we are added the weighted value of these three sounds that occur is exactly the harmonious degree value of I level chord in the first trifle, thus, we calculate each trifle harmonious degree value of chords at different levels respectively:

The first trifle:

The second trifle:

The 3rd trifle:

The 4th trifle:

Above-mentioned result of calculation statistics is obtained to statistics:

(C) calculate respectively the preparation chord of each trifle;

(C1) selecting the maximum chord value of the first trifle is I level 80;

(C2), using I level 80 as denominator, calculate respectively S1, S2, S3, S4, S5, S6 and this peaked ratio;

I /I=80/80=100%

II/I=20/80=25%

III/I=40/80=50%

IV /I=40/80=50%

V /I=30/80=37.5%

VI/I=70/80=87.5%；

(C3) >=80% whether the ratio of judging step (C2), reach a conclusion: I level and VI level be preparation chord according to this algorithm to calculate the preparation chord of other trifles as follows:

the progression of the series expression preparation chord of every trifle below in upper table;

(D) this melody is large tune, taking trifle as unit, to prepare chord as material, these chords is carried out to permutation and combination, show that some groups of chords of this section of melody connect, and obtains following permutation and combination:

The chord group of this melody and totally six groups of situations;

(E1) define chord intensity weighted value F, MF, M, the P of its variation according to the Changing Pattern of adjacent two trifle chord progression, and F=100, MF=80, M=60, P=40 form arithmetic progression, the related table of its formation is as follows:

in this form, each strong and weak numerical value represents that respectively chord progression taking its top is as current trifle, with taking its left side chord progression be after the variation tendency of a trifle; By the strong and weak table of form contrast chord degree weighted value of step (D), obtain following form:

(E2) calculate respectively the chord intensity weighted value summation that every group of chord connects;

(E3), in the result calculating, select numerical value maximum one group or wherein any one group, the 4th group, the 5th group, the 6th group corresponding chord can be served as the chord of coupling.

The above, be only preferred embodiment of the present invention, not the present invention done to any pro forma restriction, and any simple modification, the equivalent variations in every foundation technical spirit of the present invention, above embodiment done, within all falling into protection scope of the present invention.

Claims (5)

1. a method of giving known melody Auto-matching chord, is characterized in that, comprises the following steps:

(A) in any one section of melody, give each clap position weighted value by any one trifle of this melody according to its fixing beat, in each trifle, each weighted value summation of clapping position is 100; And taking trifle as unit, calculate respectively each sound in the shared weighted value of this trifle;

(B) calculate harmonious degree S1, S2, S3, S4, S5, the S6 of six grades of chords of each trifle I level to the;

(C) calculate respectively the preparation chord of each trifle;

(D) taking trifle as unit, to prepare chord as material, these chords are carried out to permutation and combination, show that some groups of chords of this section of melody connect;

(E) then according to classic harmony theoretical foundation, during each group chord is connected, every two adjacent chords carry out the calculating of sound tendentiousness degree of strength, finally draw the total value of the tendentiousness degree of strength that every group of chord connect, any one group that gets in maximum one group or maximal value is coupling chord.

2. a kind of method of giving known melody Auto-matching chord according to claim 1, is characterized in that: in described step (A), comprise the following steps:

(A1) beat of described melody is any one in 2/4 bat, 3/4 bat, 4/4 bat or 6/8 bat, and wherein the ratio of the 2/4 bat position weighted value of clapping is R1:R2, and R1>R2; The ratio of the 3/4 bat position weighted value of clapping is T1:T2:T3, and T1>T2>T3, T2+T3>T1; The ratio of the 4/4 bat position weighted value of clapping is P1:P2:P3:P4, and P1>P2>P4, P1+P2>P3+P4, P2+P3>P1, P1>P3; The 6/8 bat position weighted value of clapping is assigned as two parts, and its ratio is identical with 2/4 rule of clapping, and wherein the bat position weighted value of each part distributes rule identical with 3/4 rule of clapping;

(A2) each independent bat is divided in 4 parts and claps position, weighted value is given respectively in each interior bat position, and the weighted value sum of clapping position in each independent bat in 4 equals the weighted value of this independent bat;

(A3) melody pitch mapping, is all mapped to the perfect pitch value of all notes that occur in melody in same octave;

(A4) contraposition of melody duration is decomposed, and the sound that each is greater than 16 dieresis, splits into the set that least unit is the sound of 16 dieresis, calculates the weighted value of each 16 dieresis according to the shared bat position of each sound and interior bat position ratio;

(A5) weighted value of mapping pitch is calculated, and is unit by trifle, calculates respectively the shared weighted value of the each sound of this trifle.

3. a kind of method of giving known melody Auto-matching chord according to claim 1, is characterized in that, described step (C) comprises the following steps:

(C1) select a maximal value in S1, S2, S3, S4, S5, S6;

(C2) maximal value of selecting with step (C1), calculates respectively S1, S2, S3, S4, S5, S6 and this peaked ratio;

(C3) whether >=80% ratio that to judge step (C2), in the time of ratio >=80%, classify this kind of chord as preparation chord.

4. a kind of method of giving known melody Auto-matching chord according to claim 1, it is characterized in that, described step (D) must meet the following conditions: (D1) in the time that this melody is large tune melody, its first trifle and last trifle are I level, in the time that this melody is ditty melody, its first trifle and last trifle are VI level; (D2) chord of arbitrary neighborhood two trifles is not identical.

5. according to a kind of method of giving known melody Auto-matching chord described in any one in claim 1 to 4, it is characterized in that, described step (E) comprises the following steps:

(E1) define chord intensity weighted value F, MF, M, the P of its variation according to the Changing Pattern of adjacent two trifle chord progression, and F, MF, M, P form arithmetic progression, the related table of its formation is as follows

in this form, each strong and weak numerical value represents that respectively chord progression taking its top is as current trifle, with taking its left side chord progression be after the variation tendency of a trifle;

(E2) calculate respectively the chord intensity weighted value summation that every group of chord connects;

(E3) in the result calculating, select any a group in a group of numerical value maximum or maximal value, its corresponding chord is the chord of coupling.