An interval is the distance between two musical notes. When learning to write music intervals, you need to know the two kinds of intervals: Generic intervals and Specific Intervals
Generic Intervals (Simple Intervals)
Generic intervals (or simple intervals) are the distance between two notes measured on the staff:
first (prime) | second | third | fourth | fifth | sixth | seventh | eighth are the names of the generic intervals.
*Accidentals are ignored when counting the number of generic intervals.
Seconds, thirds, sixths, and sevenths can have a major or minor quality. Firsts, fourths, fifths, and eighths have a perfect quality. All intervals can have an augmented or a diminished (except prime) quality.
prime (perfect | augmented)
second (major | minor | augmented | diminished)
third (major | minor | augmented | diminished)
fourth (perfect | augmented | diminished)
fifth (perfect | augmented | diminished)
sixth (major | minor | augmented | diminished)
seventh (major | minor | augmented | diminished)
eighth (perfect | augmented | diminished)
In other words, specific intervals are the number of half steps between the two notes on the keyboard.
This table shows the number of half steps for each specific interval.
Major / Perfect Quality Intervals
First, let’s look at the major / perfect quality. These numbers are highlighted in red.
Major second: 2 half steps
Major third: 4 half steps
Perfect fourth: 5 half steps
Perfect fifth: 7 half steps
Major sixth: 9 half steps
Major seventh: 11 half steps
Perfect eighth: 12 half steps
Minor Quality Intervals
Minor = Major – 1
Minor second: 1 half steps
Minor third: 3 half steps
Minor sixth: 8 half steps
Minor seventh: 10 half steps
Minor intervals transform from major intervals, so only seconds, thirds, sixths, and sevenths can be minor.
Augmented Quality Intervals
Augmented = Perfect + 1
Augmented = Major + 1
Augmented second: 3 half steps
Augmented third: 5 half steps
Augmented fourth: 6 half steps
Augmented fifth: 8 half steps
Augmented sixth: 10 half steps
Augmented seventh: 12 half steps
Augmented eighth: 13 half steps
If an interval is a half-step larger than a perfect or a major interval, it is called augmented.
Diminished Quality Intervals
Diminished = Perfect – 1
Diminished = Minor – 1
Diminished second: 0 half steps
Diminished third: 2 half steps
Diminished fourth: 4 half steps
Diminished fifth: 6 half steps
Diminished sixth: 7 half steps
Diminished seventh: 9 half steps
Diminished eighth: 11 half steps
An interval that is a half-step smaller than a perfect or a minor interval is called diminished.
How to write intervals on the staff?
Here is an example:
Diminished Fifth above E
Steps to writing intervals on the staff:
1. Write the E note on the staff.
2. Write the generic fifth from E on the staff.
3. From the interval table, find the number of half steps for diminished fifth.
4. Raise 6 half steps from E on the keyboard.
5. Six half steps from E is B Flat.
How to identify and name intervals?
Steps to naming intervals:
1. Ignore any accidental & count the generic intervals on the staff.
This example is a generic sixth on the staff. Sixths can have a major, minor, diminished or augmented quality.
2. Count the number of half steps from C to A Flat on the keyboard.
There are 8 half steps from C to A Flat.
3. From the interval table, look at the generic sixth column and find the name of the interval with 8 half steps.
Minor sixth is the name of this interval.