Musical intervals are how the distances are measured between two notes, or simply; how big the space is from one musical note to the next.
It could be debated, but these distances are actually where single notes turn into music!
Intervals are the skips and leaps in a melody, they create the particular pattern of a music scale and are the building blocks for chords.
Learning about intervals will help you understand many concepts in music theory much better.
Learning to identify intervals visually and aurally, as well as to sing or play them on your instrument will also improve your note reading skills.
For interval practice, try this resource: Mastering Intervals
There are two ways to write or play an interval:
The smallest interval normally used in the music of the western hemisphere is the half step, or the semitone. This is also called an interval of a minor (small) Second.
Together with the semitone (above) the whole tone (or whole step) is one small but important interval and one of the building blocks for all common scales. This is also called an interval of a major (big) second.
Basic intervals are numbered from unison (one) up to an octave (eight).
You simply count the first note as “1” and then count each of the staff lines and spaces to the next note.
Interval number names are:
1 = Unison, 2 = Second, 3 = Third, 4=Fourth, 5=Fifth, 6 = Sixth, 7 = Seventh, 8 = Octave.
Compound intervals are musical intervals larger than an octave; 9th, 10th, 11th, 12th and 13th.
Intervals are named after their number (as you saw above) but also what is called quality.
The qualities are explaining exactly how large or small each interval is.
Quality names are: major, minor, perfect, augmented and diminished.
So, each basic interval (if found on the white keys on the piano, or using no sharps or flats) may have different qualities:
But by using accidentals (sharps and flats), the intervals can be changed to become even larger or smaller.
It is a very good idea to practice to listen to and differentiate the different intervals in music.
This is especially useful when you want to write down a melody you hear, or to be able to imagine how a melody sounds only by reading the notes.
Start by learning how a scale sounds in step wise movement (seconds). Then continue to practice how skipping a note sounds (thirds).
Then practice each basic interval separately, both melodic and harmonic, and try to associate each interval with a specific sound color or a specific song. Try this excellent free interval song chart generator.
Singing the intervals (even if it sounds terrible!:) also helps your listening, or inner hearing, so, sing along!