Previously on part 1 we discuss what music theory intervals are and some different types of intervals used in music. Review that post if you have not yet read it. Today we will define the distances that make up different intervals. We will also discuss how many intervals you have and how to count higher than an octave.
Intervals are counted by numbers. However, when we consider intervals we need to remember that each number has 3 notes in that group. For example: a half step is a second. A whole step is a second and a 3 half steps is a second. The difference between these is that a half step is a flat 2. The whole step is a 2 and the 3 half steps is a #2. What makes this confusing is that a #2 is the same note as a b3. They sound the exact same pitch. The #2 and b3 are called enharmonic minors. For example say we are in G and we play a #2 the note is A#, if we play a b3 the note is Bb. These are the exact same notes with a different name.
You can count numbers up to 2 octaves high. Once you get more than an octave you do not recount the numbers 1, 3, 5 or 7. However, the 2 becomes a 9, 4 becomes 11 and 6 becomes 13. Most of the time you see a flat or sharp 2 you call it a flat or sharp nine. Same thing goes with a sharp 4 is a sharp 11 and flat 6 is flat 13. This is called the rule of 7. If it is a 2, 4 and 6 you add seven to it to get an octave higher.
Intervals are all over in music. They make up chords and scales and lead us to our knowledge about music. Intervals are distances described by numbers. Each number has a sharp and flat possibility. You can count intervals up past an octave. If you take a number and add 7 to it you get the octave higher. Usually only 2, 4 and 6 are talked about an octave higher. This allows you to mention chord extensions and melody notes with more than an octave between the 2 notes. Memorize that 2 becomes 9, 4 becomes 11 and 6 becomes 13. This will be very beneficial to your music education and understanding of music and music theory.