Major 7 vs Dominant 7
The C major 7 and the C dominant 7 share 3 notes — C, E, G. From there, the C major 7 adds B, while the C dominant 7 adds Bb.
Piano, C3 to C5. Notes in this scale, low to high: C3 (root of C Major 7 and root of C Dominant 7), E3 (3 of C Major 7 and 3 of C Dominant 7), G3 (5 of C Major 7 and 5 of C Dominant 7), Bb3 (flat 7), B3 (7), C4 (root of C Major 7 and root of C Dominant 7), E4 (3 of C Major 7 and 3 of C Dominant 7), G4 (5 of C Major 7 and 5 of C Dominant 7), Bb4 (flat 7), B4 (7), C5 (root of C Major 7 and root of C Dominant 7).
Both scales above are drawn on one piano keyboard in the key of C. Notes belonging to both are drawn as a split two-color dot, so the notes they share and the notes unique to each are visible in one picture.
How the formulas differ
Scale degrees are the key-independent way to compare two scales — these stay the same in every key, and they are what actually distinguishes one scale from another.
| Scale | Degrees |
|---|---|
| Major 7 | R · 3 · 5 · 7 |
| Dominant 7 | R · 3 · 5 · b7 |
Notes in common
| Note | In Major 7 | In Dominant 7 |
|---|---|---|
| C | R | R |
| E | 3 | 3 |
| G | 5 | 5 |
Notes that differ
- Only in the major 7: B (7)
- Only in the dominant 7: Bb (b7)