Determining Chords in a Key

Gary Slabaugh · From: Scottsdale, AZ

I am beginning to understand things like the interval 1,3,5 would make up a major chord, and I am aware of the "Circle of 5ths". What I cannot seem to find is how does one determine the chords in a particular key, is there a formula? Specifically I am looking at a song in A flat, but I would imagine the key somehow tells me what chords are not going to be "clunkers" right?

Robert Todd · From: Atlanta, Georgia USA

Correct! Think of the key of the song as the one chord typically written I.

There are a couple of basic chord progressions that work well in every key.

I IV V

or

I V are two.

In Ab the one chord is Ab, the four chord is determined by simply counting the scale notes to four or Db

the five chord of course is Eb

There are many other formulas for songs, but start here and you will have several thousand songs to work with

[This message was edited by Robert Todd on 22 October 2002 at 07:01 AM.]

nick allen · From: France

To go one stage further:
the scale can be harmonised, which means there is a series of chords, one based on each note of the scale.
In C (to keep it simple) these chords are:

C Dm Em F G Am B7b5 C (again)
(don't worry about that B one for now

)

Unless the tune modulates (moves temporarily to a different key) those chords should work for a tune in C. Transpose for other keys, of course.
There will probably be more (and more detailed) explanations forthcoming. I think it maybe helps to take theory in small bites, one at a time...?
Nick
PS The kind of music you are playing may make a difference - hard rock, some Celtic music, etc, tends to be "modal" and follow different rules.

Doug Beaumier · From: Northampton, MA

There is a formula that will give you the common chords in any key. Here is the formula in numbers (applies to all keys):



1    2m    3m 4    5    6m 7dim

The relative chords in any key are based on the notes of the major scale. The C major scale has the following notes:



C Major Scale





C   D    E F    G    A    B C

The most common chords in the key of C are:



C    Dm    Em F    G    Am    Bdim C

In your example, key of Ab, you'd apply the same formula:



Ab Major Scale





Ab    Bb    C Db    Eb    F    G Ab

The most common chords in the key of Ab are:



Ab    Bbm    Cm Db    Eb    Fm    Gdim Ab

It's as simple as that

------------------
My Site - Instruction | Doug's Free Tab | Steels and Accessories

Rick Aiello · From: Berryville, VA USA

How 'bout this to expand on Doug's reply. It helps to explain how the individual chords are constructed (spelled) from the notes of the Tonic(Key) tone's major scale.



          Tonic Major Scale :





     (-) = a half step (1 fret)





        1--2--3-4--5--6--7-1








I      1,3,5





IIm    2,4,6





IIIm   3,5,7





IV     4,6,1





V      5,7,2  





VIm    6,1,3





VIIdim 7,2,4

Some "fancier chords"






I6    1,3,5,6


I7    1,3,5,7b


Imaj7 1,3,5,7 


I9    1,3,5,7b,2


Iaug  1,3,5#


Idim  1,3,5b,6


V7    5,7,2,4


IIm7  2,4,6,1


IIIm7 3,5,7,2


VIm7  6,1,3,5

Some songs use dominant 7ths in place of the minors:






II7   2,5b,6,1


III7  3,5#,7,2 


VI7   6,2b,3,5

[This message was edited by Rick Aiello on 23 October 2002 at 07:53 AM.]

Andy Volk · From: Boston, MA

One thing I've found helpful over the years is to buy - or even better - make a transposing chart of all the chords in all 12 keys. In the Key of C (as Doug said) the diatonic chords are:
C Dm Em F G Am Bdim C

Make a table in Word & write 'em in for all 12 keys. Eventually, you wind up memorizing the relationships.

[This message was edited by Andy Volk on 22 October 2002 at 09:15 AM.]

Gary Slabaugh · From: Scottsdale, AZ

I spent an hour awake trying to figure this out last night, and then could not sleep for an hour. You guys all replied in less time..amazing and thanks very much.

Zayit · From: Winnipeg, Manitoba, Canada

Thank you very much Nick, Rick & Doug for sharing your wisdom with us on the forum!

I never really understood those chord relationships before until now.

One question: Why are the 2nd, 3rd & 6th minors while the maj7th has a flatted fifth (dim)?

Rick Aiello · From: Berryville, VA USA

In the Key of C ...

The "Second" chord, Dm, AGREES with the harmonic overtones generated by the tonic C note ..ie 2,4,6 or D,F,A = Dm

Same goes for the "Third" and "Sixth" chords (3,5,7 or E,G,B = Em ; 6,1,3 or A,C,E = Am)

The "Seventh" chord, Bdim, AGREES with the harmonic overtones generated by the tonic C note ... ie 7,2,4 or B,D,F = Bo

Everything revolves around the TONIC Note and its Harmonic (Overtone) series ... Scales, chords, etc ....

The Harmonic series for a Tonic C note is:



C(1) - 1st harmonic (Fundamental)


C(1) - 2nd harmonic (1st overtone)


G(5) - 3rd harmonic


C(1) 


E(3) 


G(5) 


Bb(7b)


C(1) 


D(2)


E(3)


F#(5b)


G(5)


A(6)


Bb(7b)


B(7)


C(1)

Each repetitive note is an octave higher (2nd harmonic C is one octave higher than 1st harmonic C)

If you keep goin' ... eventually all chromatic notes will show up ...

It is the boosting/cutting of certain harmonics that make one instrument sound different than another (timbre) .... the boosting/cutting of certain harmonics is why tube amps and solid state amps differ in tone ... etc, etc....

I always found it interesting that the "fourth note", F, fails to "show up" early in the series .... Another thread in Steel Players recently was kinda discussing the 4th in Jazz Improvisation .... anyway...

And, Thats why we tune using Just Intonation ...

Oh My

... did I open up a can of worms with that statement

[This message was edited by Rick Aiello on 22 October 2002 at 04:01 PM.]

Terry Farmer · From: Albuquerque, New Mexico, USA

Zayit,
Check this link. The correct address is a couple of posts down. Great Stuff!

[This message was edited by Terry Farmer on 23 October 2002 at 10:59 AM.]

nick allen · From: France

That link didn't work for me

?
But to answer Zayit's question -
as Rick's chart in his first reply shows, the chords are all built up from the notes in the major scale of the I chord, i.e. the C scale in my example. And by the time you get to the B, the notes are B, D and F - which to be strictly accurate, are 3 out of the 4 notes that make a Bm7b5 or Bdim chord... They are also 3 out of the 4 notes which make up a G7 chord, which of course leads nicely back to the C (I) chord...
Note: when Rick says above that "some songs use major 7ths instead of the minors" he means e.g. D7 instead of Dm7... not to be confused with a Dmaj7 chord. (At least I hope he does! sorry if I'm putting words in your mouth/fingers, Rick

)
All the above is true, but I'm not sure how comprehensible it is... It's still quite early in the morning here! Hope it helps.
Nick
(edited to correct an error - see below)

[This message was edited by nick allen on 28 October 2002 at 12:54 AM.]

Carter York · From: Austin, TX [Windsor Park]

I just tried the link, and noticed the file extension is not correct...the url should end with ".html", not ".hmtl", it worked after I made the change...

Carter

Terry Farmer · From: Albuquerque, New Mexico, USA

Sorry about that link. Try this one. I opened it this morning. http://www.dennysguitars.homestead.com/lessonsindex1.html This is good basic music theory stuff and an explanation of modal harmony that explains why the II, III, VI are minor and the VII is diminished. Be sure to read it 5 times like the author suggests. Every time I read it I pick up something new.

Rick Aiello · From: Berryville, VA USA

Thanks Nick ... that is what I meant...I fixed it.

Bruce Clarke · From: Spain

Nick, you say that the notes B D and F are 3 out of the 4 notes that make a B7b5 or Ddim chord. Since when has a B7b5 chord had a D note in it?

Bruce Clarke · From: Spain

Rick--all that may well be true, but the simple answer to Zayzit's question is that when you form the basic triads (three note chords) on the notes of the major or harmonic minor scale you get a given sequence of major and minor chords.In other words it just works out that way.

Rick Aiello · From: Berryville, VA USA

I know I go overboard with this stuff .... but I always hated teachers who just say ... "Because, that's the way it is"

There is usually a reason for things ... especially in Physics ... and
Acoustic Phenomena is a branch of Physics ..

I try hard to explain things the best I can ...

I guess 17 yrs of teaching chemistry and physics shows in my posts ...

[This message was edited by Rick Aiello on 25 October 2002 at 07:31 PM.]

Bruce Clarke · From: Spain

Rick,I share your dislike of teachers who use the phrase "Because, that's the way it is" You will note that I did not write that. I wrote "It works out that way," but of course I really should have completed the sentence by writing "When you apply music theory, which is a branch of physics." I was guilty of sloppy terminology, for which there is no excuse, and for which I apologise.

Rick Aiello · From: Berryville, VA USA

Please don't apologize

I just thought it was a good time to try to explain my often too "detailed" responses.

[This message was edited by Rick Aiello on 26 October 2002 at 11:02 AM.]

nick allen · From: France

My apologies - not enough coffee

It should have read Bm7b5 - which I believe, VERY much subject to correction, is more accurate than Bdim, because if you extend all the chords to four notes, then the chord built on the seventh note of the C scale has B, D, F and A (which is not part of a Bdim chord).
Nick
(and now it's early on a MONDAY morning, which is even worse, and my excuse in advance if I've made a fool of myself again

)

Bruce Clarke · From: Spain

Nick, yep, it's Bm7b5, a type of chord sometimes referred to and symbolized as a half diminished seventh (just adds to the confusion.)The triad built on B in the C major scale is a diminished chord, (two minor third intervals) and adding another minor third interval produces a diminished 7th chord . It can be thought of as 3 superimposed minor thirds, or as G7-9 minus the root. That's useful when improvising over a -9 chord.

Mark van Allen · From: Watkinsville, Ga. USA

Getting back to the nature of "Key" and chords in the original post - one of the great things about thinking in terms of the numbers and chords (as above, 1maj 2min 3min 4maj 5dom7 6min 7half-dim or min7b5) is how quickly you can relate the numbers and chord positions within the scale to ear training, or playing by ear on the bandstand- for example, the thousands of songs using just the 1, 4 and 5 chords- (Think verse of "Help me make it through the night"). In C these would be C, F, G in A- A, D, E and so on. You will find that the chords have no real "sound" on their own, one at a time, but within any given key- the One chord always sounds like "home base" and the four and five chords have DISTINCTIVE sounds relative to the one chord that allows you to recognize the progression or movement of the song. If a song has just one minor chord- (think "Country Roads") it is more often than not the 6minor- in G that would be Eminor, in C, A minor, etc. The more songs you play while keeping in mind the number system, the more patterns you start to notice and HEAR or recognize by ear. For instance, most times a minor played just before the five chord will be the 2minor- (Aminor to D7 in the key of G) and can usually be substituted or inserted there even if not in the actual progression. A sound of moving up or down the scale in chords is often just that- 2m, 3m 4, 5 chords, or 5, 4, 3m, 2m... you'll start to hear more and more of these relationships. Notice also the interelationship of the chords within a key. Look at the keys of G, C, and D... already related as the 1, 4 and 5 chords in G):
G Am Bm C D7 Em F#m7b5 G
C Dm Em F G7 Am Bm7b5 C
D Em F#m G A7 Bm C#m7b5 D
Again, leaving out the 7th chords, which usually show up as passing or leading tones, not so often as Progression chords, notice that the 6m of the key of C shows up as the 2m in G, the 6m of the key of D shows up as the 3m in G, the other two chords in G being of course C and D. You can look at many progressions in light of the various 6m- 1 chord movements and resolutions. You can also use the number system for categorizing songs and progressions using outside chords (chords not in the major scale key), simply by referencing them to the position they take outside the scale: example, a song in D with a C major chord, (think "Sweet Home Alabama", or "Can't You See")- Those songs' progression being D, C, and G in the key of D. Looking at the D scale, the 7the chord "should" be C#m7b5. So folks refer to a C chord in the key of D as "the flat seven" chord, as it is flatted a half tone or one fret in position from the "normal" seventh position. Sure enough, in any other key, that progression would would still be 1- b7- 4, or in G: G, F (instead of F#), C. That "flat seven" chord has a very distinctive sound in a progression, and you can quickly learn to relate that sound to the position two frets lower than your root chord, in the same way the "four" chord sound can always be found five frets higher than the one chord position. The number system can go as "deep" as you want to follow it- from the simple often-heard country and pop substitution of a 2 major chord for a 2 minor (as occurs in the chorus of "Help me Make It Through the Night") to the jazz substitution principle of using a scale /chord a flatted 5th up from a dominant chord to automatically generate all the "outside" hip jazz tones (Db7 substituted for G7, see many other threads for some of this stuff.) Sorry for the lengthy post, but I hope this helps a bit with those who are just delving into chord progressions. Most music does follow oft-used patterns, and you can easily train yourself to recognize them- and the number system is the mental shorthand for keeping track of it all.

Forum Index > Steel Without Pedals		Next oldest topic :: Next newest topic