If you’re new to Piano, Guitar or Music Producing or have just started learning music theory, then you may have come across C7, Cmaj7, and Cmin7 chords. In this article, we're going to explain the differences simply and then show you how to build and play them.
The Difference Between C7 & Cmaj7 & Cmin7
The main notable difference between C7, Cmaj7 and Cmin7 is the quality of the chords. C7 is a dominant 7th, which is built using a major chord, adding a flat 7 (or minor 7). Cmaj7 is a major chord with a major 7. Cmin7 is a minor chord with a minor 7.
These chords sound very different from each other because of the changes in key (major or minor), or the changes in 7th.
Here's how you'd play the different chords:
- C7 (C dominant 7) – C, E, G, Bb
- Cmaj7 (C major 7) – C, E, G, B
- Cmin7 (C minor 7) – C, Eb, G, Bb
They are all 7th chords, which means they are built using tertiary harmony, meaning that they're made up from stacks of thirds. This is similar to triads, as between each note, you are able to count 3 scale notes to the next note in your chord. These gaps are called are thirds.
The difference between triads and 7th chords is that, with 7ths, you add the 7th degree of the current scale you're in to the end of the chord. This makes something we call an extension chord and adds colour to the sound.
7th chords are often used in Jazz, RnB, Soul, Gosbpel and other genres to give a smooth, cool vibe to chord progressions.
You can make the basic seventh chords using the following formulas:
- Major 7 – 1, 3, 5, 7
- Minor 7 – 1, b3, 5, b7
- Dominant 7 – 1, 3, 5, b7
- Diminished 7 – 1, b3, b5, bb7
How To Play C7, Cmaj7 & Cmin7 Chords
Creating A C7 Chord (Dominant 7)
To play a C7 chord, you would use the dominant 7 chord spelling and apply it to the major scale. So, because you're in C, you'd take the Cmajor scale and apply the 1, 3, 5, b7 formula to it. This gives you the notes C-E-G-Bb.
Dominant 7ths are built using a major third and a minor 7th. So essentially, they're just a major chord with a minor 7th on top of them. This means you could find your dominant 7th's, 7th in the same way you find your minor 7th's, 7th.
This is the easier way to do it once you have a knowledge of chords embedded in your brain and muscle memory, but it's good to know the official spelling either way.
Creating A Cmaj7 Chord (Major 7)
To play a Cmaj7 chord, you would take the major 7 chord spelling and apply it to the major scale. So, because you're in Cmajor, you would use the Cmajor scale and apply the 1, 3, 5, 7 spelling to it. This would give you C, E, G, B.
To make it easier to find for you, the Cmaj7 chord is the same as the dominant chord, but instead you're not going to flatten the 7th (minor 7)- you'll use a major 7 instead. So, if you've already got your chord shape, just take the top note and move it up one semi-tone. This will give you a Cmaj7 (starting from the dominant shape above).
Creating A Cmin7 Chord
To play a Cmin7 chord, you can either take the minor spelling (1, b3, 5, b7) and apply it to the major scale, or, you can use the 1, 3, 5, 7 spelling and start with a minor scale. Doing either of these (with Cminor or Cmajor) will get you the same result of: C, Eb, G, Bb.
A Cmin7 chord is made up of a minor third and a minor 7th. If you remember the shapes of these chords it can be easier to remember them as their minor or major intervals, rather than remembering formulas to spell them.
An Easier Way To Remember Seventh Chords
It's all well and good knowing the formulas, but this can get tiresome when you always have to work out the spelling and then count the notes in the scale.
To remember 7th chords easier all you need to know is:
- Dominant 7 – major chord with a minor 7th
- Diminished 7 – minor chord with a flat minor 7
- Major 7 – major chord with a major 7
- Minor 7 – minor chord with a minor 7
Can you see an easier pattern to remember?
When talking about major chords, use a major 7. For dominant and minor chords, use the minor 7. This is much easier to remember once you have the understanding of intervals and can pull them from memory and we'd recommend learning this way.
Is Cmaj7 in The Key of C & Cmin7 in The Key of C minor?
If you are in the key of C major, then your tonic would be a Cmaj7 chord as the notes C-E-G-B are all diatonic to C major. The same can be said of a Cmin7 chord when in the key of C minor, as the notes C-Eb-G-Bb are all found in C natural minor.
This applies to all major or minor seventh chords in any key, so, for example, Abmaj7 would be the tonic chord in Ab and Dm7 would be the tonic in D minor, etc. However, seventh chords that are the tonic in one key, can appear on different scale degrees in other keys.
Maj7 chords can be found on the first and fourth degrees in major keys, and on the third and sixth degrees in minor keys.
For example, a Cmaj7 chord can also be found on the fourth scale degree in the key of G.
The G major scale includes the notes: G-A-B-C-D-E-F#
As you can see, the fourth note in the scale is C, and the notes E, G, and B also appear, meaning we can build a Cmaj7 chord from the fourth scale degree of this key.
With Min7 chords, they can be found on the first, fourth, and fifth scale degrees of the natural minor scale, and the second, third, and sixth scale degrees of major scales.
For instance, a Cmin7 chord can also be found on the fifth scale degree in the key of F natural minor.
The F natural minor scale is: F-G-Ab-Bb-C-Db-Eb
The fifth note in the scale is C, and the other notes that form a Cmin7 chord (Eb, G, and Bb) are all found in the scale too, allowing us to build this chord from the fifth scale degree of this key.