I know, sharps and flats have been discussed several times within this booklet. But the question remains: How can we use the circle of fifths for this? I'll be happy to tell you! The circle of fifths can be used in two different ways.

On the one hand, we can immediately see how many sharps or flats there are within any given family. On the other hand, the circle tells us exactly which notes are sharp or flat.

Please note that a musical family always contains seven notes. This means that each musical family consists of a maximum of seven sharps or flats. In addition, you know by now that there are no sharps or flats in the C-major and A-minor families.

Remember that every musical family in major has a relative minor (and vice versa). So, when I refer to the position of one o'clock, I am referring to the family G-major as well as E-minor. They contain the same notes and, therefore, the same sharps or flats.

We will start by finding the number of sharps and flats. After that, we are ready to name the exact notes that these represent.

Determining the number of flats and sharps

In no time, the circle of fifths shows you how many flats and sharps there can be found within a certain musical family.

An example will make everything clear. We start again from the twelve o'clock position because there is no flat or sharp within the families of C (C-major) and ‘a’ (A-minor).

Both scales have only white keys on a piano keyboard. If we go to the right side on the circle of fifths (the one o'clock position), we arrive at G and ‘e’. They contain one sharp.

When we advance one hour on the circle, a sharp is added each time. So, the families D and ‘b’ have two sharps, A and f# have three, E and c# have four, and B and g# have five sharps, ...

Determining the number of flats

The principle is the same but in reverse. Again, starting from the twelve o'clock position, now we will move to the left. You end up at eleven o'clock where we find the families F and ‘d’ containing one flat. An extra flat is added every time we move to the next position (on the left). Within the key of Bb and ‘g’, two flats can be found. Within the families Eb and ‘c’ three, and so on.

On sheet music, you can often find some '#' or 'b' characters at the beginning of the staff. So through the circle of fifths, you can immediately see in which family the song is written.

Easy, right?

How do I know which notes are sharp or flat?

Good news: there is a simple trick to discover which sharps and flats are part of a certain family! You already know how to find almost instantly the number of sharps or flats. Now, we can combine this using the theory below.

For the notes that are sharp, we start counting to the right, starting from F or the eleven o'clock position.

For the notes that are flat, we start counting to the left from Bb or the ten o'clock position.

In practice: On the position of one o'clock or the families G-major and E-minor, there is one sharp, the note F. This means that F# is the only sharp within the family G and ‘e’.

At two o'clock (families D and ‘b’) we find two sharps, namely F# and C#. The families of A and f# have three: F#, C# and G#. Families E and ‘c’ have four, namely F#, C#, G# and D# and so it goes on.

To find the notes that are flat, we do the same, but on the left side of the circle. We start at the position of Bb and follow the cirle of fifths.

By applying this, you see that the musical families F and ‘d’ have one flat: Bb. Those of Bb or ‘g’ have two, Bb and Eb. The musical families Eb and ‘c’ have three flats Bb, Eb and Ab, and those of Ab and ‘f’ have four: Bb, Eb, Ab and Db.

This is how to find sharps and flats! There is only one problem: for flats, we count to the left, and for sharps, to the right. And since there are seven flats or sharps in certain families, there is an overlap.

For example, the seven o'clock position on the circle of fifths may represent a family that has either seven sharps (seven positions to the right from 12 o'clock) or five flats (five positions to the left).

Let’s dive a bit deeper into this principle.