4.3: Identifying Interval Quality
- Page ID
- 310488
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)We generally name the interval based upon its quality as well as its number. Intervals can be Perfect (P), minor (m), Major (M), Augmented, (A), or diminished (d). A major third (M3) is an interval name, in which the term major (M) describes the quality of the interval, and third (3) indicates its number. An interval can be described as melodic if it refers to successively sounding pitches, or harmonic if the pitches are sounded simultaneously.
To look at the quality of intervals, we will begin by looking at the intervals within a major scale. Every note in a major scale is either a major or perfect interval (starting from the tonic pitch). Below are the intervals in a major scale.
Intervals in a major scale
To be a perfect interval the upper note has to be in the major scale of the lower note. There are three intervals that are considered Perfect (P) intervals:
• Perfect 4 (P4)
• Perfect 5 (P5)
• Perfect 8 (P8)—octave
There are four intervals that are called Major (M) intervals:
• Major 2nd (M2)
• Major 3rd (M3)
• Major 6th (M6)
• Major 7th (M7)
If we take the Major intervals and make each of them a half-step smaller, they become minor (m) intervals. Because there are four Major intervals, there are also four minor intervals.
• minor 2nd (m2)
• minor 3rd (m3)
• minor 6th (m6)
• minor 7th (m7)
Here is an example of minor intervals with an F Major scale but with the 2nd, 3rd, 6th, and 7th, lowered to minor intervals.
An Augmented (A) interval occurs when a Perfect or a Major interval is increased by a half-step, without changing the note name. The following example shows a M2 increased to an A2.
Major 2nd and augmented 2nd
The following example shows the F Major scale with all Augmented (A) intervals.
Augmented intervals
As we saw previously, if we lower a Major interval by a half step, it becomes a minor interval. If we lower a minor (m) or Perfect (P) interval by a half-step, we get a diminished (dim) interval. Here are examples of each of these:
Minor 7th and diminished 7th
Perfect 4th and diminished 4th
If we want to see these intervals applied to major and minor scales, here is an example. This is an example using C Major and c natural minor scales with intervals for each scale degree as well as the quality of the interval.
Next are a couple of resources to help you understand and remember the qualities of intervals.
Example 1:
Example 2:
Interval Chart—Ascending Intervals
| Interval Name | Abbrev | ½ steps | Example |
| Perfect Unison | PU | 0 | C – C |
| minor second | m2 | 1 | C – D♭ |
| Major second | M2 | 2 | C – D |
| Augmented second | A2 | 3 | C – D♯ |
| Diminished third | dim3 | 2 | C – E♭♭ |
| minor third | m3 | 3 | C – E♭ |
| Major third | M3 | 4 | C – E |
| Augmented third | A3 | 5 | C – E♯ |
| Diminished fourth | dim4 | 4 | C – F♭ |
| Perfect fourth | P4 | 5 | C – F |
| Augmented fourth (tritone) | A4 | 6 | C – F♯ |
| Diminished fifth (tritone) | dim5 | 6 | C – G♭ |
| Perfect fifth | P5 | 7 | C – G |
| Augmented fifth | A5 | 8 | C – G♯ |
| diminished sixth | dim6 | 7 | C – A♭♭ |
| minor sixth | m6 | 8 | C – A♭ |
| Major sixth | M6 | 9 | C – A |
| Augmented sixth | A6 | 10 | C – A♯ |
| diminished seventh 9 C – B♭♭ | dim7 | 9 | C – B♭♭ |
| minor seventh 10 C – B♭ | m7 | 10 | C – B♭ |
| Major seventh 11 C – B | M7 | 11 | C – B |
| Augmented seventh 12 C – B♯ | A7 | 12 | C – B♯ |
| diminished octave 11 C – C♭ | dim8 | 11 | C – C♭ |
| Perfect Octave 12 C – C | P8 | 12 | C – C |
If you are comfortable with solfège, this may be another method for you to make sense of, and remember, intervals.