Interval reference
Major second
2 letter names · 2 semitones · C → D
A major second spans 2 letter names and 2 semitones. Both halves of that description matter: the number comes from the letters, the quality from the exact size.
Starting on C, a major second reaches D. Its shorthand is M2, and traditionally it counts as dissonance.
How big it is
Hear it from any note
The explorer starts on C up to D. Play it one note after the other and then both together — the two ways a major second turns up in music — then change the bottom note: the distance stays the same while the spelling follows the letters.
Turned upside down
Move the lower note up an octave and a major second becomes a minor seventh. The two numbers add up to nine, and the quality flips — major with minor, augmented with diminished, while perfect stays perfect.
Where you meet it
- Five of the seven steps of a major scale (C up to D in C major)
- The root to the second of a sus2 chord (C up to D in Csus2)
From every starting note
| From | Up a major second |
|---|---|
| C | D |
| C♯ | D♯ |
| D | E |
| D♯ | E♯ |
| E | F♯ |
| F | G |
| F♯ | G♯ |
| G | A |
| G♯ | A♯ |
| A | B |
| A♯ | B♯ |
| B | C♯ |