Music Theory De-mystified Blogflat

This post is one of a 2-part series of free basic music theory lessons on my blog, musictheoryde-mystified.com. You can see the complete list here. Please feel welcome to make a comment or ask a question.

The term accidental has two similar meanings:

In general terms, an accidental is a symbol that affects the pitch of a note. The main accidentals are sharp, flat and natural.
In a musical context, the term accidental is also used to describe a note that doesn’t belong to the key of the piece; the scale that the piece is based on.

Give Me A Sign…

Symbols for accidentals such as # or b are called signs, not symbols.

A sharp sign acts like a plus sign: it adds 1 semitone to the pitch.
A flat sign acts like a minus sign: it subtracts 1 semitone from the pitch.
A natural sign cancels a previous sharp or flat.

Back in our first lesson we briefly looked at sharps and flats. Here’s a reminder.

For notes on a stave, accidentals are written before the note, immediately to the left of and at the same pitch position as the notehead.
When written as text, accidentals are written after the letter.

Writing a sharp next to a note raises its pitch by one semitone, without changing its name. Sharp = natural plus 1 semitone.

For instance, B# is one semitone higher than B. C is also 1 semitone higher than B. C is a much easier name than B#, so normally you’d call that note C. However, in some circumstances, the name B# is appropriate. We will see some examples of this in the next few posts.

A flat does the opposite to a sharp. Writing a flat next to a note lowers its pitch by a semitone, again without changing its name. Flat = natural minus 1 semitone.

Again, there are occasions where an unlikely name such as Cb is more appropriate than the natural, B.

Here are some more accidentals.

The letter notes are naturals; they aren’t raised or lowered. Normally we don’t need a sign to indicate that. However, if we’ve just used a sharp or flat (e.g. F#) and we want to follow it with the natural (F), we use the natural sign to indicate that the sharp or flat is now cancelled.

Double Trouble

There may not seem any point at this stage, but a note can be raised or lowered by as much as 2 semitones! We do this using the double sharp or double flat signs.

We already had 2 possible names for most notes, now we have even more!

Double sharps and double flats aren’t that common. We don’t randomly name a note as double sharp! It requires a really good reason to use them.

Nonetheless, notes are named according to their function in the music and sometimes their use is appropriate. If you see one, don’t worry – it’s just more of the same, “sharp sharp” or “flat flat”…

Sharpen And Flatten

To sharpen or flatten means to raise or lower a note by 1 semitone while keeping the same note name. For instance, if we change an F to an F# or a Bb to a B, we have sharpened it. You might ask, “why would we change any notes in a scale?”

In real life, we’re talking about musical pieces, not scales. Most music doesn’t just stick with the one scale for the whole piece. Also, notes can be changed temporarily just for effect, such as an ornament.

The note naming rule requires that each note in the scale has its own letter. If a note temporarily replaces a scale note it must use the name of the note it replaces. We use an accidental to make it the right pitch.

For example, if F and G are both scale notes and we want to write the note in between, it’s name depends on whether it replaces F or G in the scale. If it replaces F, it’s sharpened (= F#). If it replaces G, it’s flattened (= Gb).

Some scales have lots of sharps or flats. The note which is sharpened may already be a sharp in the scale. In that case we use a double sharp. Similarly, if we flatten a note that was already a flat it becomes a double flat. Double sharps and double flats, although fairly rare, are no big deal…

To sharpen a note is to raise it by 1 semitone without changing its name. A double flat becomes a flat, a flat becomes a natural, a natural becomes a sharp and a sharp becomes a double sharp.
To flatten a note is to lower it by 1 semitone without changing its name. A double sharp becomes a sharp, a sharp becomes a natural, a natural becomes a flat and a flat becomes a double flat.

If you change the note name, you are NOT sharpening or flattening, you’re using a different note!

Try These

Grab a pencil and a piece of paper and try some sharpening and flattening. Actually doing it is the best way to learn…

Sharpen the following notes:

Bb, C, G#

Flatten the following notes:

C#, A, Db

Answers at end of post.

This post is one of a growing series of free basic music theory lessons on my blog, musictheoryde-mystified.com. You can see the complete list here.

Please feel welcome to like, comment or to share this post. If you have any questions, pleased leave them as a comment and I will respond as soon as I can. If you enjoy my posts and would like to be kept up to date, please subscribe.

NEXT LESSON: 10. How To Find The Notes Of A Scale

PART 1 CONTENTS: Basic Music Theory Course Contents

—-

Answers

If note names mean nothing to you, start here…

In my posts:

A PIECE is any musical work.
A PART is one instrument’s component of a piece.
An ENSEMBLE is any combination of instruments collaborating to perform a piece, be it one person singing and playing, a band, choir or orchestra.

Note names

Most musicians are familiar with the note names A to G. After G comes A again and the pattern continues repeating from the lowest pitches to the highest.

A B C D E F G A B C etc.

Over the audible pitch range there are many A’s, many B’s and so on.

From one A to the next is an octave, as is from any letter to the next instance of the same letter.

Octaves

Notes which are an octave (or several octaves) apart enjoy a special relationship. When played together, the higher note blends in to the lower note. If they’re perfectly in tune (that’s for a later post), the higher note blends in so well that it almost merges inside the lower note. Even when played one after the other, what we hear sounds more like a change in register (or voice) than a different note.

Try this on your instrument. If you can play two notes at once or play one and sing the other, the effect will be the clearest, but you can still tell by playing one after the other.

Now try combinations of two different notes, such as A and G or A and C. None feel as closely connected as when they’re an octave apart (or a unison; two notes of exactly the same pitch).

In musical terms, in an ensemble, any part can be played an octave higher or lower without clashing with the other parts. All chords or harmonies will still fit. It is because of this relationship that notes which are octaves apart can, and do, share the same note name.

Intervals

The difference in pitch between one note and another is called an interval. A to the next A, an octave, is an interval, A to G is an interval, F to C is an interval.

Intervals can be measured in octaves and semitones. Each octave is divided into 12 musically equal intervals called semitones. This gives us 12 different notes, the 13th being an octave. The semitone is the centimetre (or inch) of pitch.

On a piano, 1 semitone is the interval between consecutive keys, regardless of the key’s colour.
On a guitar, 1 semitone is the interval from one fret to the next (or from an open string to the first fret).

We started with the letters A to G, followed by A etc. that’s 7 letters, the 8th being the octave of the first (as it happens, octave means 8th). So how do 7 letters add up to 12 semitones?

Not all letters are 1 semitone apart: in fact, most are 2 semitones apart. This is how the letters are spaced:

A . B C . D . E F . G . A
2 1 2 2 1 2 2 = 12

This means that 5 of the 12 different notes (per octave), the ones represented here by dots, have no name.

On a piano keyboard, all the named notes are white keys. You can see when two white keys are 2 semitones apart because there is a black key to represent the so far un-named note between them.

Piano keyboard layout showing naturals for 1 octave

On a guitar, you can find the named notes by starting on an open string, then following the above pattern by skipping a fret for every 2-semitone interval. The dots above represent the frets you skip.

Guitar fingerboard layout, A string, showing naturals for 1 octave

The named notes are called naturals. The un-named notes can be described as being 1 semitone higher or 1 semitone lower than the nearest natural.

Sharps and flats

Any natural can be raised by 1 semitone by adding the sharp symbol, #.
Any natural can be lowered by 1 semitone by adding the flat symbol, b.

For instance, the note between A and B could be called A# (A plus 1 semitone) or Bb (B minus 1 semitone).

This may seem confusing: we’ve gone from having no names for some notes to having two names. Fear not. For now, either name will do. The most common note names in general terms are:

A Bb B C C# D Eb E F F# G G# or Ab

Once we look at the notes in the context of a piece of music, the choice of note names will matter but by then it will be quite obvious which names to use. The correct note names for a piece are based on its key, a subject for a future post.

The graphic below shows how any natural can be raised by 1 semitone by adding a sharp or lowered by 1 semitone by adding a flat, resulting in two possible note names for most notes. Notice that even some of the naturals have an alternate name, although their use is relatively uncommon in most keys.

In my next basic post we will look at how note pitches are written on a stave.

Try These…

How many semitones between the following pairs of notes? (count up from the first note until you reach the second note of the pair):

A to C
A to C#
A to E
A to G
Bb to F
B to F
C to A
C# to A
D to Bb

Answers at the end of this post.