Theory Part One

Tones and semitones

When you play different notes on your guitar, some sound higher and some lower. We need some way to describe this difference in sound and the different intervals between notes. In Western music we have a system that uses Tones and Semitones. On the guitar, if you play a note then move up one fret, the difference between the two notes is a semitone. If you move up two frets, the difference is a tone. Using the notes you have learnt so far, here are some of the intervals.

E to F: Semitone

F to G: Tone

B to C: Semitone

C to D: Tone

What do you think the interval is between D and E? Clue: Think about when you used relative tuning.

Of course there are other intervals. What about E to G, or B to E. We'll come on to that later when we talk about scales.

Time signatures

Remember when we first described the stave. We mentioned that the top 4 in 4/4 means four beats in the bar, but glossed over the bottom 4 in 4/4. What this tells us is that each beat lasts for one crotchet.

A crotchet is also sometimes called a quarter note. So 4/4 = four quarter notes.

One beat is one crotchet