There are many kinds of ninth chords, and they can be used in different ways. This post explores different kinds of ninth chords and how you can use them, with plenty of examples of their use in popular music.
In “Use substitution chords to spice up your songs,” I provided examples of various chord substitutions songwriters and performers can use to liven up their jams and compositions. In that post, I mentioned one way to spice up your songs is to turn your seventh chords into ninth chords. But there are many diverse kinds of ninth chords, and they are used in different ways.
What is a ninth chord?
In western music, the notes of a chord are given numbers, starting with 1 on the root. So, for example, in C: C is 1, D is 2, E is 3, all the way up to 8, which is the C that is one octave higher than the root. But we can keep going past 8. The next note, D, is 9. All ninth chords feature either a major or minor chord with the addition of the ninth note.
Note: Because they feature so many notes and can be difficult to play on stringed instruments (like a guitar or ukulele), you can always leave out the fifth note of any ninth chord. Leaving out the fifth doesn’t affect the quality or the use of the chords and can often give these ninth chords some much-needed space.
Dominant ninth chords
These are the most common ninth chords in popular music and are heard frequently in jazz, R&B, blues, and funk. If someone casually says “play a ninth,” this is what they mean. A C dominant ninth chord is written as C9.
Dominant ninth chords function the same way dominant seventh chords do, and in fact, they include a dominant seventh as well as a ninth. A dominant ninth chord includes 1-3-5-♭7-9. (A C9 includes C-E-G-B♭-D.) Any dominant ninth chord can be substituted for the same dominant seventh, they just give the music a funkier or jazzier feeling. James Brown used dominant ninth chords all the time; perhaps his most famous example is “Papa’s Got a Brand New Bag.” You can hear the guitar playing an unaccompanied E9 after James sings the title.
Dominant ninth chords can also be used for moody effect, as it is in Led Zeppelin’s “The Rain Song.” Check out how Jimmy Page slides from A♭9 to G9 at :29. In fact, this moment also offers a nice example of a tritone substitution, only using ninth chords in place of sevenths.
Flat ninth chords
From the most popular ninth chord to one of the least, the flat ninth chord is also known as a dominant minor ninth, or dominant seventh flat ninth. Though it is rarely used in popular music, it turns up frequently in jazz. Flat ninth chords are usually written as C7♭9, though they can also be written as C7(♭9), C7(-9), or C(-7-9). (Like I said, the names and notation can be confusing.) A flat ninth chord includes these notes: 1-3-5-♭7-♭9. C7♭9 would be C-E-G-B♭-D♭.
Flat ninth chords can also be used instead of dominant seventh chords, though they sound more dissonant than either the seventh or dominant ninth chords. The flat ninth feels like it needs to be resolved more than a dominant ninth chord does. While you can use a dominant ninth chord to give a song a funky feel (a la James Brown), the flat ninth won’t work that way. Perhaps the most famous example of a flat ninth in rock is in the Beatles’ “I Want You (She’s So Heavy).” They hammer home an E7♭9 again and again at the end of each chorus. You can hear it in the intro and again throughout the song whenever this intro section is playing.
“Caroline, No” by the Beach Boys also features a nice use of the flat ninth chord. You can hear it on the word “watch” in the bridge, “It’s so sad to watch a sweet thing die” (1:04 in the video).
If you’re looking for more bite or anguish in your dominant chord, try a flat ninth instead.
Sharp ninth chord
The dominant seventh sharp ninth chord is sometimes called the Hendrix chord as it was famously used in “Purple Haze.” Like all dominant chords, this features a flat seventh. A C7#9 would include these notes: C-E-G-B♭-D#.
This ninth chord is rather unusual in that it doesn’t necessarily behave the way other dominant chords do. In jazz it can often be used to resolve to a I7; in rock, the chord is used for jarring effect as the I chord, as it is on “Purple Haze” and the Beatles “The Word.”
Minor ninth chords
So far all of the chords we’ve explored have been built on major triads (e.g. C-E-G). Ninth chords can also be built on minor triads. A Cm9 chord would be C-E♭-G-B♭-D. Minor ninth chords offer a lush way to expand on any minor chord, and you can easily swap out your ii or vi chord (Dm or Fm in the key of C) for a minor ninth instead to create a moodier or jazzier feel. Al Green’s “Let’s Stay Together” is littered with minor ninth chords, though the most prominent is the Gm9 on the chorus. You can hear it when he sings the word “Let’s.”
Although minor ninth chords feature a flat seventh, they don’t feel like they need to be resolved like their major dominant counterpoints do.
Pink Floyd’s “Breathe” is worth mentioning here. Em9 is the first chord of the song and you can hear it at the beginning of every line. But (bonus points!) the song also features a nice turnaround using a sharp ninth chord and a flat ninth:
G D7#9 D7♭9
Is all your life will ever be
Run rabbit run
All of the chords we’ve featured so far use a flat seventh note, which makes the chords feel like they need to be resolved. The following ninth chords don’t use a flat seventh, and so they have a more ornamental feeling than a functional one.
This is simply a major chord with an added ninth note. A Cadd9 would be C-E-G-D. Add9 chords are often used to sustain a single note throughout a progression. All of the chords in the verse and chorus of Oasis’ “Wonderwall” feature a ringing D note. The chorus starts on a Cadd9 chord.
You can also play minor add9 chords. Again, the ninth note is merely added on to a minor chord. A Cmadd9 chord would feature C- E♭-G-D. The Police’s “Every Breath You Take” features both major and minor add9 chords to nice effect. Each chord feels wider, like they have more (ahem) breathing room.
Major ninth chords
The naming convention is a little confusing with this one. The “major” in the name “major ninth chord” actually refers to the seventh and not the ninth. So far all of our ninth chords have used a flat seventh. Major ninth chords use a major seventh, so Cmaj9 would use these notes: C-E-G-B-D. Because there is no flat seventh in this chord, this chord doesn’t feel like it’s pulling you toward another chord. Instead you get a big, juicy ‘70s-R&B-style chord. It sounds so big because you’re essentially playing two major chords at the same time. A Cmaj9 consists of both a C major and a G major chord. Any time you would use a maj7 chord you can easily substitute a maj9 chord instead for a fatter, fluffier sound that makes people want to strap on some roller skates. Katy Perry’s “Birthday” opens with an Emaj9 chord.
This last “ninth” chord is an unusual one. This chord features a major triad with an added sixth and an added ninth. (A C6/9 includes these notes: C-E-G-A-D.) It’s an unusual ninth chord because it doesn’t quite sound like a ninth chord at all. In fact, it feels more like a bigger sixth chord. Examples in popular music are hard to find, but 6/9 chords abound in jazz. Typically, on a piano, they are played wide, in stacks of fourths. You can hear that big 6/9 sound in the playing of McCoy Tyner on John Coltrane records.
One famous song that heavily features a D6/9 chord is “A Horse with No Name” by America. It’s basically a two-chord song, with the second being a far-out 6/9 chord. The voicing on this tune isn’t the greatest, so I wouldn’t use this song to determine whether a 6/9 chord is in your future.
There are plenty of great videos on YouTube that show you how to best voice a 6/9 on piano and guitar. It’s a wonderful chord that can add a big splash of color to your song. It’s a great chord for jazz or even for country or Americana.
Play around with all of these ninth chords. Guitarists may find some of these chords harder to play than others. Minor ninth chords sound particularly great on guitar. Flat ninth chords… not so much. Try them out and use them to change up any ho-hum progressions in your own songs or to give your cover songs a unique spin.