Intervals

Now, on to intervals!

You can measure almost anything. usually with a ruler. However, in music we measure distances with intervals.

There are only two types of intervals you need to know to have a sound understanding of how to play basic chords. These are semitones and whole tones or half-step and whole-step.

Semitones 

A semitone is the distance between any two keys on the keyboard that are right next to one another.

As you can see, the distance represented by each of the red lines is a semitone (half-step)

Whole tones

A whole tone is the distance between any two keys which skip one key in between. That is, a whole tone is comprised of two semitones and is often noted as the distance between two white keys as they skip over one black key.

It is easy to get confused with wholetones. As such I have accompanied the next image as well to help clarify.

Do not get confused with the distance here. A whole tone (whole step) from E will take you to an F#, not an F. Similarly, a whole tone from D# will take you to an F, not an F#.

Nonetheless, if you just keep in mind that a whole tone is made up of two semitones everything should make sense. 

Recap

A semitone is the distance going to the next or previous note.

A whole tone is the distance going to the note after the next or previous note.