Lesson 7: Small Intervals

An "interval" is the space between two notes. Shall I be obvious? A small interval is a situation where there are two notes close together! There are three small intervals to be dealt with in this lesson: semitone, whole tone, and tone-plus-semitone.

We have already dealt with the semitone in lesson 3. Now you need to know that there are two types of semitones. Both sound exactly the same, but they are written differently. Take a look at this example:

Both of these semitones sound exactly the same. Play them on your instrument. From your knowledge of semitones, you know that if you were to play both examples on a musical instrument, you would play the same notes! In other words, the point here is that G# and Ab are exactly the same pitch. But here's the difference: we would say that in the first example, "G-sharp is a DIATONIC semitone lower than A". In the second example, we would say "A-flat is a CHROMATIC semitone lower than A".

So there are two types of semitones: DIATONIC SEMITONES and CHROMATIC SEMITONES. Here are quick definitions:

Here are some more semitones, correctly labeled:

(You will learn in later lessons that a diatonic semitone is also called a minor 2nd)

A whole tone equals the distance of two semitones. Looking at this view of a piano keyboard, you can see two notes indicated by dots:

The 'G' and the 'A' are one whole tone away from each other due to the fact that there is a note in between them: the G-sharp, or A-flat. This distance of two semitones is called one whole tone or whole step.

To write whole tones or whole steps, we begin by ensuring that they've been placed on the staff correctly. Whole tones are written on the staff so that if one note is on a line, the other must be on the space above or below it. If one note is written on a space, the other must be on the line above or below it. However, just because two notes are placed on a staff in this manner, don't automatically assume they are whole tones. Take this interval, for example:    The 'E' is on the line directly below the 'F'. But as you can see from the diagram of the keyboard above, these two notes are only one semitone apart- there is no black note in between them. The rule about placement of the notes on the staff is only part of the procedure. You must now adjust the second note, if necessary. In this case, you would add a sharp to the second note in order to make it a whole tone higher:    There is one other place on the keyboard where there is no black note between white notes: between 'B' and 'C'. So a whole tone above 'B' would be 'C#'.

Here's a quick definition:

Here are some written whole tones:

   
Notice that whole tones are written on adjacent lines or spaces. (You will learn in later lessons that a whole tone is also known as a major 2nd.)

A tone-plus-semitone is the distance of three semitones. On paper, it must be written so that if one note is on a line, the other note must be in the space above or below it. If one note is in a space, the other note must be on a line above or below it. And just as with the situation regarding whole tones, do not assume that because you have placed the notes correctly on the staff that they are automatically a tone-plus-semitone apart. You must then adjust the second note so that the proper interval exists.

Here are some written tone-plus-semitones:

(You will learn in later lessons that a tone-plus-semitone is also known as an augmented 2nd.)