Intervals
An interval is the distance between any two notes. Intervals are named in numbers which are larger or smaller depending on how many letter names apart the notes are. For example, C to D is the interval of a second (C=1, D=2), C to E is the interval of a third (C D E = 1 2 3), C to F is the interval of a fourth, etc.
There are actually various different types of intervals (major, minor, etc) but an in-depth study of intervals is beyond the scope of this book. At this stage it is enough to be aware that different notes can be specific distances apart based on their letter names and the number of semitones between them, and that these distances are called intervals.
If you wish to pursue music more seriously, it is important to understand and be able to hear all the different intervals. Any good vocal or instrumental teacher will be able to help you with this.
