Tutorial :: Chords in a key of 'X' : know everything about it!

Discussion in 'Guitar Lessons, Tutorials & Tips' started by amit82cse, Jul 18, 2005.

  1. amit82cse

    amit82cse Silent observeR

    Ok, Here is my attempt to explain the chords in a particular key of note. I will take the mathematical model approach to explain it properly.

    The very first question asked is: what "Chords in a Key of 'X'" really means?
    In this section I will educate you to interpret and understand this statement by soul. So lets elaborate the statement little bit more...

    If one says that Z1, Z2, Z3, ...Z7 (where Zn belongs to set of all chords for n=1 to 7)
    are the chords in the KEY OF 'X' (where 'X' belongs to set {A,B,C,D,E,F,G} or {Am,Bm,Cm,Dm,Em,Fm,Gm})

    It means that ALL the notes in Zn (n=1 to 7) will be present in the scale 'X'.

    Take an example of 'Key of C'.

    So lets first find out what are the notes in the scale C. If you dont know how to find the notes then just assume that by some means we have come to the following set of notes for a scale C.

    C scale :: C D E F G A B

    So according to the definition stated above, all the notes in all the chords in the key of C MUST be from the above set. It means that there can't be any #(sharp) or b(flat) note in any of its chors.

    Lets confirm this.

    Below are the chords in the Key of C. (I will shortly come to know on how to get this set)


    Now, if you take any chord from this set and list down notes in that chord, all the notes must be presetn in the C scale.

    So got the picture on what "Chords in the key of 'X'" means? If NOT then read it again. Its very important that you understand what it means before we dig into how to get the chords in any key.

    Once you understand what "Chords in a Key of 'X'" means, its prime time to know how to get this set.

    If scale X contains following notes..

    x1, x2, x3, x4, x5, x6, x7

    You can get a chord for a given xi (where i=1 to 7) treating xi as the ROOT note in that chord. This way you can form 7 basic chords from the notes in the key of X. This set of 7 chords is what formed the "Chords in a Key of 'X'".

    Again take an example of chords in a key of C.

    As we mentioned notes in C scale are :: C D E F G A B. Hence from each note we will create a new chord treating that note as ROOT note. This way we will form all the chords.

    C --> Cmaj
    D --> Dmin
    E --> Emin
    F --> Fmaj
    G --> Gmaj
    A --> Amin
    B --> Bdim

    Wow, you must be happy that you have just revealed that secret of "Chords in a key of 'X'". But wait a minute, dont you want to know how to create a chord for a give note xi (where i=1 to 7) provided that notes in that chord MUST complies with the statement made in section [[1]]?

    Lets go to the next section then...

    Ok, here is the real fun in forming the chords from a given note.
    Lets summarize the notations once again.

    Scale X contain notes :: x1, x2, x3, x4, x5, x6, x7

    Chords in the key of X are :: Z1, Z2, Z3, Z4, Z5, Z6, Z7

    Whats the relationship...

    x1 --> Z1
    x2 --> Z2
    x3 --> Z3
    x4 --> Z4
    x5 --> Z5
    x6 --> Z6
    x7 --> Z7

    Zi (where i=1 to 7) is formed of some notes. Our aim is to find these notes. For this we write the scale of xi...

    Scale xi :: ti1, ti2, ti3, ti4, ti5, ti6, ti7

    We start with Major triad of xi and modify it according to the statement made in section [[1]] to come to the final Zi.

    Following details will help us creating a desined triad.

    Major triad: 1 3 5
    Minor triad: 1 b3 5
    Diminished triad: 1 b3 b5

    It means that major triad of xi will contain the notes at the position 1, 3 and 5. For minor triad we flatened the note by one fret at position 3. For diminished triad we flatened the note at position 3 as well as at position 5 by one fret each.

    So lets start with assumption that Zi = major triad of xi = ti1 ti3 ti5

    Now pay attention, if notes ti1, ti3 and ti5 are present in the scale of X which is x1, x2, x3, x4, x5, x6, x7 then your assumption was right and you have got the Zi.

    Hence mathematically,

    ti1 = xi for some i (where i= 1 to 7)
    ti3 = xi for some i (where i= 1 to 7)
    ti5 = xi for some i (where i= 1 to 7)

    For each i (=1 to 7) you will start with this process and if above three conditions meet then your Zi = xi major chord.

    But some times one or more conditions stated above fail. In those cases we tried minor triad or diminished triad by flatening the ti3 to ti3b and/or ti5 to ti5b. Flatened note thus generated must be present in the xi set.


    ti1 = xi for some i (where i= 1 to 7)
    ti3b = xi for some i (where i= 1 to 7)
    ti5 = xi for some i (where i= 1 to 7)

    will give you Zi = xi minor chord.


    ti1 = xi for some i (where i= 1 to 7)
    ti3b = xi for some i (where i= 1 to 7)
    ti5b = xi for some i (where i= 1 to 7)

    will give you Zi = xi diminished chord.

    Thats all. You have find out the chords in a key of 'X'.

    So take a complete example for key C.

    Scale C contain notes :: C D E F G A B

    Your first chord will be a C chord, because C is the first scale degree. Now, since this is a C chord, it will be based on the C major scale. Take notes 1 3 5 as shown below:
    Note: C D E F G A B C
    1 2 3 4 5 6 7 1
    This gives you notes C, E, and G. Since all 3 of those notes are in the key of C, you do not have to modify them to fit, and you have a major triad (1 3 5). So your first chord is C major.

    The second chord will be a D chord, because D is the 2nd scale degree. It's based on the D scale, which is D E F# G A B C# D. Now, take 1 3 5 of this scale:
    Note: D E F# G A B C# D
    1 2 3 4 5 6 7 1
    This gives notes D F# A. This presents a problem - F# is not in the key of C! In order to keep this chord in key, we have to flat the F# (lower it by 1/2 step) down to F natural. This gives D F A, which is scale degrees 1 b3 5 of the D major scale. 1 b3 5 is the formula for a minor triad. Therefore, your second chord is D minor.

    The seventh chord will be a B chord, because B is the 7th scale degree. It's based on the B scale, which is B C# D# E F# G# A# B. Now, take 1 3 5 of this scale:
    Note: B C# D# E F# G# A# B
    1 2 3 4 5 6 7 1
    This gives notes B D# F#. D# (3) and F# (5) are not in the key of C, and must be flatted to D (b3) and F (b5), respectively. This gives us scale degrees 1 b3 b5, which is the formula for a diminished triad.

    By applying this pattern, you can quickly figure out that the chords in the key of C are:


    Well for any major scale the pattern will be the below one...

    1 - major
    2 - minor
    3 - minor
    4 - major
    5 - major
    6 - minor
    7 - diminished

    So for Chords in key of G will be :: G Am Bm C D Em F#dim
  2. ssslayer

    ssslayer Banned

    WOW !!!

    thats very nice and precise ... man u cud write a book ...

    but ya know the onli prob is that not many ppl here are from math background ... and they'll get "disturbed" soon after reading ... even tho the text and the matter is not exactly mathematical ... (u know how ppl are afraid of math terms like axioms etc ...)

    hey i just have one ques ... i believe the question itself is wrong ... but still i have seen numerous examples of this happening: in key of Aminor ... the scales they use are usually Am, Dm ... (all the chords u've written for C maj) ... however someplaces i have seen D7 as the chord ... instead of Dm ... (yeah this is what i have found written in some places) ...

    b.t.w. the dimished chord and diminished scale run is one of my favorite ... sounds like malmsteen, toni iommi ...
  3. deathdr_87

    deathdr_87 Awesome Guitarist

    ok im sorry it seems jsut too lnog to read.. im sure its all correct - it seemd like it when i went trhroguh it.. its simple really though... to find all the chords in a scale (normally im a math guy but this is rather simple to explain) -
    to find the chords in a scslae - write out the scale: eg. C major: C D E F G A B C. Then draw a table with 3 columns and 7 rows...
    fill out the table like this: inthe first column fill in the scale again. this is the column of the roots of the chords.. then simply fill in the next 2 columns y skipping a note each... eg... C E G or D F A.... these will all form chords...

    im quite sure u explained the same thing using maths.. good work...
  4. amit82cse

    amit82cse Silent observeR

    Good Question.

    Actually, when i said that you have to create a chord, i took you toward the MAJOR TRIAD which consist of notes at position 1,3 and 5.


    You can also form the EXTENDED CHORDS in which you use notes at position 1,3,5 and 7. Now when you include 7th note, chord becomes one of the 7th flavor.

    Major 7th: 1 3 5 7 - Abbreviation: maj7
    Minor 7th: 1 b3 5 b7 - Abbreviation: min7
    Dominant 7th: 1 3 5 b7 - Abbreviation: 7, dom7
    Minor/Major 7th: 1 b3 5 7 - Abbreviation: min/maj7

    This way you can get the chords in the key of C as...

    G7 OR Gdom7
  5. ssslayer

    ssslayer Banned

    thats ok ...

    my ques is ... suppose i am playing in the key of E minor ...
    now ... some places i have come across being written that Bdom7 is in the scale of E minor ...

    i used to believe that B minor is there in the scale ... even Bm7 ... but B7 ???
    howww ? ...

    thats y i said that i feel mebbe the question itself is wrong ...
  6. grv

    grv New Member

    small question

    @amit : true CS guy ;) hey nice tutorial/information ...

    i'm a newbie... and what's worse is i have a question

    guys when we talk about the chords in the key of say C... then is it like generally when the solo part or the notes in a song are in C Major scale then the chords for the rhythm will come from the set of chords that we talked off here...

    would really like to see much info of this type...
  7. ssslayer

    ssslayer Banned

    yeah that s basically what happens ...

    even if u dont follow the rules of music ... it so happens that your brain will unknowingly follow it ... and lo ... u see that the music u have made is actually in a scale ... its funny ... but it happens ...

    infact whenever u dont follow these rules ... the music stands out ...
    like if i play E major chord instead of E minor chord (in the same key of C major) ... it will immediately strike u ... that tension in music is what makes it slightly off-key and exotic ...
  8. grv

    grv New Member


    hey thnx for the reply...

    yes it does happen with the solos... whenever i try to tab a solo i find that it is mostly in the notes of a scale (mostly major)... i don't get the chords easily though for a song... also i have a little problem getting a working strumming for a song msot of the time i find my strum very lame for the song...

    nyways thnx again
  9. deathdr_87

    deathdr_87 Awesome Guitarist

    @sslayer - im not sure i understood ur question... ur asking is B7 in E minor... tjhe truth is not strictly.. wat u mgiht end up playing thoug is B5 m7th.. thats a B minor chord with the third but with the added minor 7th.. when u writer out the ntoes - this is very similar to B7 but it essentially not the chord...

    ppl writing music in the key of E minor can most definitely make use of the B7 and add a very different sound to the song... it should sound good in the key of E minor if used properly because only 1 note is off.. that brings in the possiiilty for diffferent modes to be used over that chord....

    another possibility is using a B7sus4 chord... that is in the E minor scale (sus4 means no major 3rd) and the B phrygian mode can e used to solo over it...
  10. ssslayer

    ssslayer Banned

    B7sus4 ... woweee ... now thats the kinda sound i'd likta include in songs ...

    there is one more ... the one that Blackmore plays in "Strange kinda woman" intro ...
    dunno the name ... i guess this is what the chord is ... (reverse engineered so no guarantee of correctness) ... one of my fav sound ...

    e --(7)----------
    b ---10--------
    g ---9---------
    D ---8----------
    A ---9---------
    E ---7----------

    play the bracket note if u have more than 5 fingers ... on your hand ...
  11. deathdr_87

    deathdr_87 Awesome Guitarist

    that chord is impossible to annotate in sheet music.. theres a good chance it wont exist in any other song anywhere...

    dunno how he managed to think of it.. he includes 3 chromatic notes all in 1 chord.. ppl dont do that often.. really nice chord.. i worked out 2 diff finger positiios to hold that chord.. let me know if u want them... all killer ones of course...
  12. deathdr_87

    deathdr_87 Awesome Guitarist

    (sorry for double post) - this resolves to E major i think
  13. shankarbn

    shankarbn New Member

    Simplest way

    The simplest way to know what key is...

    The key is nothing but the root note of the scale.. simple as that.. i always wonder why ppl make it so hard for themselves.. but the detailed explanation is good for ppl who want more of theory though..

    Very good work nonetheless..
  14. mj2009

    mj2009 New Member

    @amit hey nice one bro...
  15. palthestud

    palthestud New Member

    great note man..thanks
  16. alevainnage

    alevainnage New Member

    Tutorial Chords in a key of X know everything about it

    Hi darkAudax,

    I am running your tutorial on the Backtrack Live CD. I have got to point where I am running aircrack-ng and it is now up to 600000 IVs but still no WEP key. I know the WEP key and it is a 64bit open system.

    I noticed that you mentioned that it needed a wired client to access the AP but I don't have that at the moment but when I tcpdupm the arp-request-dec file it with my WEP ket it gives me the results you say it should so in your opinion should this work?


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