Jamplay.com Holiday Special

Welcome to the forums!

what is I-IV-V chord progression

Post your question here and an experienced guitar player or teacher will get back to you.

Moderator: The GN support team


Postby stebob » August 30th, 2004, 11:57 pm

I have been playing for a few months now and keep seeing I-IV-V chord progression popping up - what is it guys I'm confused?

Thanks
SteBoB
stebob
newbie
 
Posts: 3
Joined: August 30th, 2004, 11:56 pm

Postby Musenfreund » August 31st, 2004, 1:40 am

It's the first, fourth, and fifth chord of a progression and the basic formula for the twelve bar blues.

Read David's lesson on Before You Accuse Me. It's an excellent explanation of the I IV V formula.

Welcome to the Madhouse!
Well we all shine on--like the moon and the stars and the sun.
-- John Lennon
User avatar
Musenfreund
Guitari Lama
 
Posts: 8581
Joined: September 15th, 2002, 6:20 am
Location: Nutopia!

Postby markminni » August 31st, 2004, 5:23 am

Example in the key of A

A Major Scale: A,B,C#,D,E,F#,G#,A
I chord would be an A chord
II chord would be a B chord
III chord would be a C# chord
IV chord would be a D chord
V chord would be an E chord
VI chord would be F# chord
VII chord would be G# chord

I,IV,V would be an A,D,E chord progression
I,IV,V7 would be an A,D,E7 chord progression
I,ii,IV,V would be an A,Bm,D,E (lower case Roman numerals imply minor)
User avatar
markminni
newbie
 
Posts: 36
Joined: August 25th, 2004, 6:07 am
Location: New York

Postby Slydog » August 31st, 2004, 11:51 am

To expand on what Markminni said, in each key you have a standard seven chord progression. Find the scale for the key, then you get this pattern:

I - ii - iii - IV - V - vi - VIIdim
Major-minor-minor-Major-Major-minor-diminished

So in the key of C, the scale is:

C-D-E-F-G-A-B

and the chords are:

C maj - D minor - E minor - F maj - G maj - A minor - B diminished
which are the I-ii-iii-IV-V-vi-VIIDim chords respectively.

So, I-IV-V would be C-F-G

This works for any key, with the notes in the scale giving rise to the chord in the progression.
Blame it on the lies that killed us, blame it on the truth that ran us down.
User avatar
Slydog
Full Member
 
Posts: 430
Joined: January 1st, 2004, 3:44 pm
Location: Cincinnati

Postby Musenfreund » August 31st, 2004, 2:23 pm

Be sure you know how to build a scale as well.
The chord progression follows the notes of the scale. Markminni gave you the scale for A (key of A).
This article --Theory without Tears explains the basics of key and scale if you need that info too.
Well we all shine on--like the moon and the stars and the sun.
-- John Lennon
User avatar
Musenfreund
Guitari Lama
 
Posts: 8581
Joined: September 15th, 2002, 6:20 am
Location: Nutopia!

Postby stebob » September 1st, 2004, 9:37 am

thanks guys - great info, things are becoming clear :D
stebob
newbie
 
Posts: 3
Joined: August 30th, 2004, 11:56 pm

Postby hbriem » September 2nd, 2004, 3:19 am

There are 12 notes in the equal tempered instruments everybody uses these days, hence 12 keys. Each key uses 7 out of those 12 notes. Here are the notes for the different keys:
Code: Select all

Key        Minor     Signature      1   2   3   4   5   6   7
C  major   A  minor                 C   D   E   F   G   A   B
G  major   E  minor  #              G   A   B   C   D   E   F#
D  major   B  minor  ##             D   E   F#  G   A   B   C#
A  major   F# minor  ###            A   B   C#  D   E   F#  G#
E  major   C# minor  ####           E   F#  G#  A   B   C#  D#
B  major   G# minor  #####          B   C#  D#  E   F#  G#  A#
F# major   D# minor  ######         F#  G#  A#  B   C#  D#  E# 
F  major   D  minor  b              F   G   A   Bb  C   D   E
Bb major   G  minor  bb             Bb  C   D   Eb  F   G   A
Eb major   C  minor  bbb            Eb  F   G   Ab  Bb  C   D
Ab major   F  minor  bbbb           Ab  Bb  C   Db  Eb  F   G
Db major   Bb minor  bbbbb          Db  Eb  F   Gb  Ab  Bb  C
Gb major   Eb minor  bbbbbb         Gb  Ab  Bb  Cb  Db  Eb  F


Now, building chords from those notes, is known as "harmonising the scale and is done by picking every other note from the scale (note that 9=2, 10=3, 11=4 and 13=6):
Code: Select all
Degrees of notes         C major scale notes
1 2 3 4 5 6 7 8          C D E F G A B C         Chord no.  Chord name. 
-------------------------------------------------------------------------
1   3   5                C   E   G               I          C major
  2   4   6                D   F   A             ii         D minor
    3   5   7                E   G   B           iii        E minor
      4   6   8                F   A   C         IV         F major
        5   7    9               G   B   D       V          G major
          6   8     10             A   C   E     vi         A minor
            7    9     11            B   D   F   vii°       B diminished


Thus the primary chords of each key, the I, IV and V are major and the secondary chords, the ii, iii and vi, are minor. The diminished chord, the vii°, can be thought of as a substitute for the V7 (5-7-9-11) and they function the same.

Minor keys are a little more complicated. In Aeolian mode or natural minor (1-2-b3-4-5-b6-b7-8), the i, iv and v are minor. In practice, that sounds very sedate and undramatic, so in practice people usually use a major or dominant V or or V7. This gives rise to the harmonic (1-2-b3-4-5-b6-7-8), and melodic (1-2-b3-4-5-6-7-8), minor scales.
hbriem
Guitarnoise Denizen
 
Posts: 1257
Joined: June 20th, 2002, 12:40 am
Location: Reykjavik, Iceland