Chords By Number

2019-02-10T18:34:01+00:00June 5th, 2015|Categories: Bass Playing Fundamentals|Tags: , , |11 Comments

Chords within a key can be numbered to more easily understand the functional harmony of a song and to also aid in memorising chord progressions.

In the early stages of playing we often we see songs as just long streams of unrelated chords but it’s important to know that the same chord patterns appear time and time again. Learning these patterns by number can help recognise sequences in any key and also give you a better understanding of they all relate to each other.

This Lesson is a preview of the Bassic Fundamentals Course 

Numbering The Major Scale

We can assign a number to each degree of the major scale by starting from the root and working up.

D  E  F  G  A  B  C
  2  3  4   5   6   7  8 

We can then build a chord off of each degree and add the chordal quality.

Chord I – Major
Chord II – Minor
Chord III – Minor
Chord IV – Major
Chord V – Major
Chord VI – Minor
Chord VII – Diminished

In the key of C major the chords would look like this:

Chord I – C Major
Chord II – D Minor
Chord III – E Minor
Chord IV – F Major
Chord V – G Major
Chord VI – A Minor
Chord VII – B Diminished

Memorising this is easier if you remember that chords I, IV and V are major. All the rest are minor except for VII which is diminished. 

This sequence of chords is exactly the same in every key. Here’s G major for example:

Chord I – G Major
Chord II – A Minor
Chord III – B Minor
Chord IV – C Major
Chord V – D Major
Chord VI – E Minor
Chord VII – F# Diminished

Chord Progressions By Number

Now we’ve numbered every chord in a key, we can begin to refer to chord sequences in the same way. Take this progression for example:

C Major | A minor | D minor | G Major

We know that we are in the key of C Major, so the first chord must be chord I. Then we can simply count up the scale to find out what the other chords are.

| Am | Dm | G
I   |  vi     ii   | V

Now we know the sequence, we can transpose the chords into any other key. Here is the sequence in G:

| Em | Am | D
I   |  vi     ii   | V

Every chord in a key has its own sound and transposing chord sequences will help you hear how each chord relates to its scale.

Roman Numerals 

Chord numbers are often represented by their roman counterparts.

1 – I
2 – ii
3 – iii
4 – IV
5 – V
6 – vi
7 – vii

Capitalised numbers represent major chords.

Lowercase numbers represent minor chords.

Recognising Common Chord Sequences

Chords I, IV and V are what we call primary chords. They are used in thousands of songs so it is really important to know what they sound like so you can recognise them by ear.

As an exercise, create your own short sequence using chords I, IV and V in C. Play through this sequence a few times and then try transposing it to a new key. You will hear how the sequence sounds the same despite using different notes. To take this exercise further, use other chords in the key such as ii and vi so you can hear how they are used alongside the others.

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  1. Jim Batt June 6, 2015 at 2:23 pm - Reply

    making the most of your lessons,and especially the progression of each lesson to the next,well done.

  2. Liza Nicklin September 13, 2015 at 4:49 pm - Reply

    This lesson is excellent – thank you so much! 🙂

  3. eric young September 27, 2015 at 9:50 pm - Reply

    wonderful and enlightens lesson for me thank you very very much

  4. AUGUSTINE STEPHEN October 1, 2015 at 3:07 pm - Reply

    You are a awesome online BASS GURU!!!!!!!!!!!!

  5. Ray B October 24, 2015 at 4:13 am - Reply

    Great Video! What about if you are playing in a Minor chord instead of a Major? Does the same progression apply Maj,min,min,Maj,Maj,min,Dim,?


  6. Majdi November 4, 2015 at 8:03 pm - Reply

    Cheers mate .. Great lesson .. I’m already enjoying advancing with you bit by bit! great stuff

  7. Will Greenlee December 28, 2015 at 4:56 pm - Reply

    Great job! Thanks for making it easy to understand!

  8. carl huffman March 17, 2016 at 5:31 am - Reply

    Mr mark great lesson really but isn’t this just the Nashville numbering system which is also fantastic for transposing eartraining and changing keys of songs for your singer all you bass guys are missin the boat on all of that and country music as well and there isn’t bubcus on you tube for country players granted the older stuff was shall I put it very basic but the country from the 80’s thru now is tricky to play quick chord changes and lots of pickups lead in riffs that are very fun to play and I love and play in a rock band classic to present and a country band to I love them both but my heart is with jazz fusion and old soul stuff love ballads and up beat but I love to play anything because whatever you play it’s all related sooner or later I can put jazz riffs in rock or country and vice versa but it would be nice to have some off beat country and blues turn arounds your a great teacher and I love how you explain things but a little of that to would be great for many players and yes I can funk and double thumb with some of the best and although I am not a beast I am a brute lol at the age of 45 and started by ear at the ripe old age of 8 but from a very musical family that was very hard on me but I have always been lucky enough to play with the best musicians any area I lived just luck and hard work

    • MarkJSmith March 17, 2016 at 11:27 am - Reply

      The Nashville number system is just a new name someone thought up (in Nashville) for a system that’s been in use through pretty much all of tonal music history. Chords are numbered using roman numerals very early on in classical harmony study. Many people seem to think it’s a practical consideration so you can learn things really quick and transpose easily. Which is true. It does help in that regard, but the main (and much deeper) reason for looking at chords in this way is as a means of understanding the tonal relationships between chords with a key with a view to analysis and composition.

  9. Pat Calabrese April 3, 2016 at 3:10 am - Reply

    The scale climb in the Led Zeppelin song “Heartbreaker” is a great song to use when learning progressions in modes

  10. Shawn Manning February 11, 2017 at 1:20 pm - Reply

    Its amazing listening to you teach. And the fact that you take the time is even more amazing. I could follow you all day. Thank you for sharing your awesome tallent and gift.

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