Major Seventh Chord
A major seventh chord combines a major triad with a major seventh. Cmaj7 contains C, E, G and B. Compare it with C7 and C6, then arrange the root and seventh so their one-semitone pitch-class relationship remains clear without crowding the low register.
- 1-3-5-7
- major triad
- major seventh
related pages
Which notes are in Cmaj7?
Use the formula 1-3-5-7:
- C: root
- E: major third
- G: perfect fifth
- B: major seventh
Common symbols are Cmaj7, C major 7 and C triangle 7. CM7 may also appear, although notation conventions vary.
How do you build it?
Start with C major, C-E-G, and add B.
B sits eleven semitones above C and one semitone below the octave C. Count C-D-E-F-G-A-B to confirm that it is a seventh.
Transpose the formula rather than copying white keys. Fmaj7 is F-A-C-E; B-flatmaj7 is B flat-D-F-A.
Where does it occur in a major key?
Major-seventh chords occur diatonically on degrees I and IV.
In C major, they are Cmaj7 and Fmaj7. Cmaj7 can function as tonic; Fmaj7 can function as subdominant.
The same structure takes different functions from its scale degree and progression.
Is a maj7 chord always stable?
No chord type has one fixed function.
Cmaj7 can act as tonic in C major, IV in G major or a temporary color elsewhere. Its B may still move to C in a melodic voice.
It lacks the E-B-flat tritone of C7, so it does not create the same dominant resolution toward F.
Why can voicing change it so much?
C and B are adjacent pitch classes. Placing B immediately below C in a low register can make their interaction prominent.
Spread C into the bass and place E-G-B higher for more separation. Put E or B on top when the melody requires it.
Spacing, timbre and volume change the balance; the chord notes and name remain Cmaj7.
What is the difference between Cmaj7 and C7?
Cmaj7 uses B natural. C7 uses B flat.
C7 contains the tritone E-B flat and commonly functions as V7 of F. Cmaj7 contains E-B, a perfect fifth, and often functions as I or IV in a major key.
One semitone changes both the chord symbol and common voice leading.
What is the difference between Cmaj7 and C6?
Cmaj7 is C-E-G-B. C6 is C-E-G-A.
Both extend a major triad. C6 includes a major sixth and no seventh; Cmaj7 includes the leading tone B.
C6 and Am7 share the pitch classes C-E-G-A. Root, bass and progression determine which name fits.
Which scales fit Cmaj7?
C Ionian contains the chord tones and adds D, F and A.
C Lydian changes F to F sharp, producing sharp 11 above the chord. It is often chosen when the natural 11 F clashes with E or the harmony explicitly marks Cmaj7 sharp 11.
Use melody and progression to choose between them.
How do inversions work?
Cmaj7 has four positions:
- Root position: C-E-G-B
- First inversion: E-G-B-C
- Second inversion: G-B-C-E
- Third inversion: B-C-E-G
Cmaj7/B places the major seventh in the bass. Follow B upward to C when the bass line calls for that motion.
Which notes can you omit?
Keep E to show major quality and B to show the major seventh.
The unaltered fifth G is usually the first omission. C can be omitted when a bassist clearly supplies the root.
A shell voicing E-B lets the bass complete Cmaj7 with only two keyboard notes.
How should you practice it?
Build Cmaj7, C7 and C6 by changing only B, B flat or A.
Play every inversion and name the bass note. Then connect Cmaj7-Am7-Dm7-G7 with minimal upper-voice movement.
Record a close low voicing and an open high voicing to compare register without changing pitch classes.