What Are They?
Intervals are the distances between each note. They are named numerically and have different qualities to them based on the exact spatial difference.
C to a D is a MAJOR second
C to a Db is a MINOR second
C to a E is a MAJOR third
C to a Eb is a MINOR third
Why Are They Important?
These small differences may feel arbitrary, but intervals actually play a big role in how we perceive music. Intervals have always been categorized as consonant or dissonant; consonant means stable, and dissonant means unstable. With that definition, it is obvious that the perception of intervals is subjective…who decides what is stable and what is not?
Fortunately in music today, there are no such quick and fast hard rules on what is considered consonant or dissonant, and many intervals can be used to achieve a variety of effects. Furthermore, what classical music considers as dissonant, jazz music may consider neutral or even consonant. Different musical styles have different customs on how to approach and resolve dissonances
The concepts of intervals is important, because it is the music between the notes. For example, a singer reaching for a perfect fifth (C – G), will sound considerably different than reaching for a major 6th (C – A). Not only is the latter a higher note, a good singer also understands that there is a different quality to the interval, therefore requiring a different tone and approach to singing it.
This holds true for piano players as well. As piano players, it may be easy for us to think an interval is simply using different fingers. However, if we approach music this way, we may find it to be robotic and lackluster. It is the space between the notes, that creates the interesting and beautiful sounds that we call music. We do not speak in monotone, so we should not play in monotone either.