The Complete Idiot''s Guide to Music Theory

Chapter 2:Intervals

Two half steps equal one whole step. The interval between F and G is a whole
step; the interval between B and C-sharp is also a whole step.

Now that you know about steps, it’s a little easier to understand how sharps
and flats work. When you sharpen a note, you move the pitch up a half step.
When you flatten a note, you move the pitch down a half step.

Take the note C, for example: When you add a flat to C, you take it down a half
step. Because the first key (white or black) to the left of C is the white key B,
this means C-flat equals B. When you add a sharp to C, you take it up a half
step. The first key to the right of C is the black key we call C-sharp. (This black
key is also the first key to the left of D, which means C-sharp is the same as
D-flat.)

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In some musical

circles, a half step is called

asemitone,and a whole

stepis called a tone.

Definition

On a guitar, a half step is

the distance of a single

fret. A whole step is the

distance of two frets.

Note

While the half step is the smallest interval in Western music,music from

other parts of the world often contains intervals smaller than a half step.

Some Indian music, for example, divides an octave into 22 steps, each

about half as large as a Western half step.

Tip

You can use the step method to describe the intervals between two notes—
although once you get more than a few steps away, the counting becomes a tad
difficult. When you’re trying to figure out which note is seven half steps above
middle C (it’s G, in case you’re counting), it’s time to use another method to
describe your intervals.

A Matter of Degrees

A more accepted way of describing intervals is to go back to the seven main
notes of a scale—and revisit the relative numbering method. You can use the
numbers of the scale to denote the basic intervals between notes, and thus apply
this numbering to any scale.

First Things First

As you learned in the previous chapter, you can use numbers to describe the
seven main notes in any scale. The first note is numbered one, the second note
is numbered two, and so on. This method of numbering actually describes the
seven degreesof a musical scale.

There also are fancy musical names you can use in place of the numbers, which
you might run into in some more formal situations. The following table pre-
sents these formal degree names.