Octave Subdivision

 One octave consists of 6 whole steps, one step consists of 2 half-steps, and one

half-step consists of up to 100 cents. What that means is that, for example, D

and D# are one half-step apart but between them there are up to 100 cents. Cents

in music are typically used to express microtones, which are very small

intervals—smaller than a half-step (which you can also call a semitone).

Figure 4: Most software programs that work with sound files allow you to change the pitch in

octaves, semitones and even cents

Beyond one semitone, rather than using hertz as a frequency measure unit

(which if you remember shows the amount of air pressure waves produced in a

given amount of time), we more often use cents which are a logarithmic measure

used for musical intervals. It is enough to say that they are simply more

convenient and easier to use for musicians. Human ear is very sensitive as it can

recognize up to only a few cent difference between two successive notes

(pitches), but the interval of one cent is too small to be heard between two

successive notes.

Your instrument can be in tune and still sound a little bit off, and that’s the case

when there’s a small pitch difference that can only be measured in cents.

Correcting these small differences is sometimes called fine-tuning and the tuners

that you can find today allow for this kind of super-accurate tuning (with even

less than one cent accuracy). The more “exactly” in tune your instrument is, the

better it will sound, especially on the recording. That’s why it is important to

keep it in tune.

We’ve now covered the notes and the note circle. Before we dive any further, it

is essential that you understand and learn the intervals in music.