An ‘add’ chord is simply a TRIAD with an added note. The added note can occur within the triad, making it an ‘add2’ or ‘add4’, or outside the boundary of the triad (but within the same octave) making it a 6th or 7th chord. If the ‘added’ note extends into the next octave, you’ve crossed into the realm of add 9, 11 and 13 chords.
In this section, you’ll find the following subjects:
Now I know there are going to be some purists that will freak out about the information presented on this page and that’s okay because it’s really not for them anyway. It’s for those that are trying to get a basic grip on the process — and for that purpose, this is a pretty solid start.
First up – voicings.
There are 2 types of voicings: OPEN and CLOSED.
A CLOSED VOICING occurs when all of the chord notes fall within a single OCTAVE like the Cadd2, Cadd4, CMaj6 and CMaj7 chords shown below. An OPEN VOICING occurs when the chord spans into the second OCTAVE like the Cadd9, Cadd11 and Cadd13 MAJOR chords.
ADD 2 & 4 CHORDS
The following graphics show C MAJOR add 2 & 4 triads with the ‘added’ note in green.
While the Cadd4 shown above is technically correct, you probably wouldn’t want to play it because of the dissonance created by the single half-tone INTERVAL between the iii (e) and IV (F) scale degrees.
If you “drop” the dissonant III (e) note of a Cadd4 chord, it actually becomes a Csus4 chord (C, F, G) and much more consonant.
MAJOR 6th & 7th CHORDS
If the added note occurs outside of the triad, but within the octave, the chord becomes either a 6th (9 half-tones from the ROOT) or a 7th (11 half-tones from the ROOT) as shown in the following graphics.
Add 9, 11 & 13 CHORDS
Now, compare the above to the Add 9, 11 and 13 chords below.
Did you notice that the Add 9, 11 & 13 chords have the same ‘added’ notes an OCTAVE higher than the add 2, add 4 and C MAJOR 6 chords respectively? This means that the Add 9, 11 & 13 chords will sound slightly higher (or possibly lower if inverted) than the single OCTAVE chords because of the “tension” note.
See the drop notes page to learn how to deal with tone and tension notes that are a single half-tone apart like in the Cadd11 shown above.