What Is That Chord? Explaining 2nd and 9th Chords

There are a number of chords that include the 2nd note of the scale, and you'll find this as extremely common in contemporary worship music. You'll see either a "2" or a "9", and you'll find that they are the same note. Then when used in various combinations with other notes, you get a nice collection of chord variations. Let's see what they are and what makes each one unique to itself.

NOTE: This article is a part of our "Music Theory In Worship" series, and if you haven't read the intro article to the series, we highly recommend that you do! READ IT HERE!

Now, take the C major scale for example:

The second note in the scale is "D". So, in the key of C, if you referred to the "2nd", it would be a D as the 1st (or the root) would be C. The root triad (3-note chord) in this key would be C-E-G. Now, let's look at different C chords that utilize the 2nd note in the scale.

C2 : While some in a music theory argument would debate that this is not a valid chord (I would have in years past), this is extremely common in worship music. This is a very simple chord that replaces the 3 with a 2. So it's only a 3-note chord and the notes would be C-D-G. If you add any other notes, then it would no longer be a C2. You may sometimes see this incorrectly labeled as a Csus2. This is incorrect as "sus" (suspended) is intended for usage with the 4 as it gives a sound of "suspense" where the 4 naturally wants to resolve to the 3. That is not what is happening in a C2 with the 2nd. This is simply a variation of the major triad that gives a little different and more open sound.

Now, if you continue the scale above beyond the 8th note (C), you would get to the 9th, which is a D. We've just used a "D" in the C2 chord, which is the 2nd. So, the 2nd and the 9th are both a D, but the difference comes in the voicing of the chord and also other understood elements in chord structure. For example, in the C2, the 2nd is used instead of the 3rd. Simple. In any other chord, that "D" is going to be referred to as a 9th.

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When you go beyond the triad and 7th chords, you get into more complex chords that are labeled as extended tertian chords. These are when you start seeing 9, 11 and 13 in your chords. Once you get beyond the 7th note in a chord, you'll only see odd numbers 9, 11, and 13.

Whenever you have a 7 or higher in a chord, the 7 is always understood... meaning it is included unless stated otherwise. Also, that 7th defaults to a flat-7th. So, in the key of C where the 7 is a B, if you see a C7, C9, etc, that 7 will be B-flat since the 7 is understood to be flat. However, when you see "maj" in the chord name, like Cmaj7, this is indicating that the 7 will NOT be flat, and instead be the natural 7th of the scale.

Cadd9 : As was explained above that a 9 would automatically assume that a 7 is included, the "add9" chord is an exception to that rule! Per the name of the chord, you are literally just adding the 9 to the major triad. So you'd take your C-E-G and just add a 9, which is the D. This is generally voiced more as a 2, meaning it's not put on top of the chord in a 9th position.

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What makes a chord the chord that it is, is the notes that are or are not included. The voicing does not matter! Meaning, the order that you put the notes on your instrument does not alter what the actual chord is. It only gives slight variations to the sound, how the chord is heard. For example, a chord with C-E-G-Bb is a C7... and if it is voiced as Bb-C-E-G, or G-Bb-C-E, it is still a C7.

C9 : As explained above, you can see in this 9 chord that the flat-7 is included by default. And, while not required, the 9 is often voiced at the top of the chord. Now, this chord contains 5 notes, but you do not have to play all 5. This is why the "G" above is blue. This is the least important note in the chord and you could leave it out without affecting the overall chord. So, drop the G and the chord is still a C9.

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The 5th note of a major scale is referred to as the dominant. Despite the name, it is the first note to go if you run out of fingers to voice your chord! The 5 adds support to the root, but it is never the deciding factor of establishing what the chord is.

Cmaj9 : While the 9 automatically includes the 7 and it is flat by default, the maj9 chord removes the flat on the 7th. The 7 is still included, but remains the natural 7 of the scale. Again, the dominant 5 is least important and could be dropped if needed. But the natural 7 along with the 9 and the 3 is what makes this chord a major 9. This is a beatuiful chord that will be heard mostly in slower, more worshipful songs.

Cm9 : Now we have the minor version of the 9 chord. First, the 7th remains as the default flat-7, so in the key of C, the Bb. Then, the big difference that separates a major chord from a minor chord is the 3rd. If you flat the 3rd, this makes your chord a minor chord. So in a Cm9 chord, the Eb is what makes it minor. Then the D adds the 9th. Without the D, and just with the Bb (7th), you'd have a Cm7. Again, the dominant 5 is the least important note in this chord.

C6/9 : One more 9th variation to review here, and that is the 6/9. This is much less common, but does pop up every so often. The big difference in this chord is that it breaks the rule of the 7th being included in extended tertian chords. What happens here is that a 6 is used instead of (not in addition to) the 7. So, in a C chord, you'd play an "A" instead of a "B" or "Bb".

Now that you have an explanation of the different 2 and 9 chords, you can better understand what to play when you see them on a chord chart next time! Sure, you can get away with just playing that root chord and ignoring the 9, the 2, etc, but you will lose out on the specific sound that was written and is expected. You should always be learning and improving on the gift that God gave you, so take the time to practice and learn how to play these different chords on your instrument. Also, be sure to learn the chords in all keys so you get comfortable playing them whether it's a C9, a G9 or a Eb9!