Section 5.2 How to Identify Perfect, Major, and Minor Intervals
Here are two methods for identifying intervals.
The first method involves thinking of the lower note of an interval as the tonic (the first note of the scale). Remember that all the notes above the tonic in a major scale are perfect or major. Determine if the upper note is in the major scale. If it is not, determine if the interval is a half step smaller than a major interval, in which case it is a minor interval.
If the lower note of an interval has a sharp or flat on it, cover up the accidental, determine the interval, then factor the accidental back in.
The second method is to memorize how many half steps there are in each interval. To determine the size of an interval, count the number of half steps between the two notes then refer to your memory.
| Number of half steps | Name of interval | Number of half steps | Name of interval |
| 1 | m2 | 7 | P5 |
| 2 | M2 | 8 | m6 |
| 3 | m3 | 9 | M6 |
| 4 | M3 | 10 | m7 |
| 5 | P4 | 11 | M7 |
| 6 | Tritone* | 12 | P8 |
* A “tritone” is a generic name for an augmented fourth (\(\left.\text{}{+}\right.\)4) or diminished fifth (\(\left.\text{}^{\circ}{}\right.\)5). These two intervals are enharmonic. Augmented and Diminished Intervals are discussed later in this chapter.
