Music Theory De-mystified Blogcourtesy accidentals

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 make a comment or ask a question.

Note: Students who solely use text notation can skip this lesson. Text notation seldom uses key signatures so sharps and flats are written after every instance of a note. In text notation, accidentals are indistinguishable from notes in the key which have a sharp or flat.

What Is An Accidental?

The term accidental has two meanings.

An accidental is a general term for a sign affecting the pitch of a note, such as a sharp, flat or natural sign.
Within a key, an accidental is the term for a note that has been sharpened or flattened, so that it’s no longer part of the key. Sharps or flats that are part of the key signature are not considered to be accidentals.
The following refers to how accidentals are used within the context of a key signature.

Unlike key signatures, accidentals only last within a bar and they are only applicable to the same octave: if the same note is used more than once in a bar, at the same octave, the accidental is only written for the first one.

The exception to this is that accidentals aren’t used in the middle of a tie, even if the tie crosses a barline. This is because tied notes are considered to be a single, longer note.

An accidental only lasts till the next barline.
An accidental only applies to a single note pitch. The same note at another octave requires it’s own accidental.
An accidental lasts the full length of a note, including tied notes. No accidental is used within a tie, even if it crosses a barline.

Courtesy Accidentals

An accidental lasts until the end of a bar. In the next bar, the note automatically reverts back to the key signature. As a reminder, this can be indicated by a courtesy accidental.

An example of this is the descending 7th and 6th notes in the melodic minor examples from the previous lesson, B3. Melodic And Harmonic Minor.

Courtesy accidentals, also known as cautionary accidentals, are sometimes written in parentheses () to indicate that each is only a reminder that a note is restored to the key signature.

Although not strictly necessary, it’s common practice to include courtesy accidentals. Whether or not you use parentheses is a matter of personal choice.

Example

The example below is in G melodic minor, requiring E natural and F# as accidentals when the melody ascends.

Accidental is only used at the beginning of a tied note, even if it crosses a bar.
Courtesy accidental because there is an F# in the previous bar, even though, as the end of a tied note, it is not written (see point 1).
Accidental is used for the first instance of each octave of a note within a bar.
Accidental is only used for the first instance of a note within a bar.
Courtesy accidental even though it’s in the key signature, because it was sharpened in the previous bar.

Ties And Slurs

A tie is a curved line that joins 2 notes of the same pitch to produce one longer note. It is placed adjacent to the notehead, opposite the stem.
A slur is a curved line that joins 2 (or more) notes of different pitches to indicate legato; full-length notes that are not articulated separately within the slur. It is placed adjacent to the notehead, opposite the stem.

Ties and slurs look the same. The only difference between a tie and a slur over 2 notes is the pitch.

Note: if the tied note is within a slur, the tie is always written closest to the notehead.

What if we wanted a slur to join a sharpened note at the end of a bar with its un-sharpened version at the start of the next bar? How can we distinguish this from a sharpened note tied over the barline?

In this case, the slurred note would receive a courtesy accidental, whereas there’s never an accidental within a tie.

Try These…

In the short melodies below, every note that’s sharpened is written with an accidental. Cross out any accidentals that shouldn’t be written and add any courtesy accidentals (or if you prefer, rewrite the exercises with the correct use of accidentals).

For example,

The answers, at the end of this post, show courtesy accidentals in parentheses. Parentheses are optional.

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NEXT LESSON: B5. Inversions Of Intervals

PART 2 CONTENTS: Basic Music Theory Course Contents

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Answers to Try These…

A Potted History Of Modes And Scales

Early Western music was based on modes. Religious music favoured those modes which had a solemn quality appropriate for worship. Secular music favoured modes suited to dance music and ballad singing.

The earliest recorded Western music, back in the 9th century, is Medieval plainsong; religious chants which were sung in unison. In Medieval times, secular music was somewhat more innovative, first by accompanying a melody with a drone and percussion, and later by layering several melodies on top of each other to form pieces called motets. The resulting “harmonies” were quite different to what we consider harmony to sound like nowadays.

During the Renaissance era, from the 14th century to the beginning of the 17th century, everything was done on a large scale, and music was no exception. Famous composers were commissioned by the Church to create ever more grandiose works, to be performed in the great cathedrals of Europe. By now, the combined melodies were crafted to produce rich harmonies. Renaissance music was still based on the Medieval modes but notes were organised harmonically as well as melodically, producing a more sophisticated sound.

By the 17th century we had entered the Baroque period, where music was sponsored as much by the royal court as the Church. Secular music flourished in high society and the sombre tone of some of the modes became unfashionable. The Ionian mode, most frowned upon by religious society for its frivolous nature, became the prominent mode of the time, to the point where it became known as the major scale.

The major scale is different to most of the other modes in that there is only 1 semitone between the 7th note and the octave, whereas in most other modes it is 2 semitones. From the Baroque perspective, this provides a sense of resolution that most other Western modes lack.

Harmony as we know it had developed, with melodies now being accompanied by chords. Along with this came the sense of key. It became possible for a piece to start in one key and visit another key.

Baroque music has many of the characteristics we can recognise in popular music of the 50’s and 60’s such as simple rhythmic structures, chord progressions, parallel (close) harmonies, and in particular the popular use of the major scale.

As popular as the major scale was, there was still a need to express the darker musical emotions. The Aeolian mode provided this to some extent and became known as the minor scale. However, it was still considered too reminiscent of the starker sounds of earlier times.

Three Types Of Minor

During the early Baroque period two variations of the minor scale were developed, called the melodic minor and the harmonic minor. As their names indicate, they were initially developed for use in melodies and harmony respectively.

To distinguish between these and the original minor, we often refer to the Aeolian mode as the natural minor.

Collectively, regardless of which variation is in use, we just use the term minor, based on the key signature.

Melodic Minor

Below are the scales of A major and A natural minor. By having both on the same root note, we can compare their character.

Listen to the the Aeolian scale, the natural minor. As a melody, it doesn’t arrive very strongly at the octave compared to the major, due to the 2-semitone interval from the 7th note to the octave. It’s a bit reminiscent of the modal sound of medieval times.

It turns out that, although parallel major and natural minor scales have 3 different notes, the most musically significant difference between their modes is the 3rd note. The 3rd is 4 semitones above the root note in the major scale and 3 semitones above the root note in the minor scale.

As long as we have the minor 3rd, the character feels like minor.
If we start to play a minor scale but finish like the major scale, we get the best of both worlds. We still have the essential character of the minor mode but a more “melodic” flow up to the octave at the end.

The problem is, when you play these notes descending, it sounds weird. It feels like we’re listening to the major scale until suddenly, right near the end, we hit the minor 3rd. It’s a bit of a shock!

The solution composers settled on is a hybrid.

On the descent, the natural minor flows quite well. The 2-semitone jump from the 7th to the octave that made it so ungainly (from the Baroque perspective) on the ascent isn’t an issue when descending. If anything, it helps the descent get started. Have a listen:

This leaves us with a new kind of mode, unlike any other mode we’ve seen so far; one that goes up one way and comes down another way. The 6th and 7th notes of the minor are sharpened while ascending but are returned to their key signature while descending.

Because the changed notes are temporary, they can’t be shown in the key signature. Instead, they are written as accidentals. If you’ve forgotten how accidentals work, see 9. Accidentals, Sharpen And Flatten.

Courtesy Accidentals

Note that on the descent, the 7th and 6th notes are written with natural signs, even though that’s part of the key signature. This isn’t strictly necessary because they’re not in the same bar as the sharpened notes, but it’s common practice to put them in when they’re in the following bar. These are called courtesy accidentals or cautionary accidentals. We will learn more about how accidentals are used in the next lesson.

How To Find The Notes Of The Melodic Minor

Start with the natural minor
When ascending, sharpen the 6th and 7th notes. Remember, a flat becomes a natural, a natural becomes a sharp and a sharp becomes a double-sharp
When descending, cancel the sharpened notes (a double-sharp becomes a sharp, a sharp becomes a natural and a natural becomes a flat)

Try These…

Write out the following melodic minor scales for 1 octave ascending and descending, in 4/4, in either the treble or bass clef
Use the rhythm of the example below
For each scale, write the key signature and use accidentals as needed

Example

G melodic minor
E melodic minor
Bb melodic minor
C# melodic minor

For bonus points, name the relative major of each scale…

Answers at the end of this post.

The Harmonic Minor

The harmonic minor was developed to make it possible to play a major chord on the 5th note of a minor scale. As we haven’t looked at chords yet in this course, I will leave the full explanation of the harmonic minor till a later lesson.

Unlike the melodic minor, the harmonic minor’s notes are consistent. Only the 7th note is sharpened, both while ascending and descending.

Because only the 7th note is sharpened, the harmonic minor has a 3-semitone interval between the 6th and 7th notes. As a melody, this gives it a rather exotic quality, as none of the standard Western modes have a 3-semitone interval between consecutive scale notes. Hence it is less-often used for melodies than the melodic minor.

Like the melodic minor, the sharpened note is not reflected in the key signature. Both melodic and harmonic minors are considered variations of the natural minor and in fact, often the same piece can incorporate both variations.

How To Find The Notes Of The Harmonic Minor

Start with the natural minor
Sharpen the 7th note, both when ascending and descending

Try These…

Write out the following harmonic minor scales for 1 octave ascending and descending, in 4/4, in either the treble or bass clef
Use the rhythm of the example below
For each scale, write the key signature and use accidentals as needed

Example

D harmonic minor
B harmonic minor
F harmonic minor
G# harmonic minor

For bonus points, name the relative major of each scale…

Answers at the end of this post.

Augmented 2nd

The harmonic minor is a good example of the need for alternate interval names.
As intervals, consecutive scale notes are called 2nds. When they are 1 semitone apart the interval is a minor 2nd and when 2 semitones apart the interval is a major 2nd.

The interval between the 6th and 7th notes of the harmonic minor is 3 semitones. Consecutive scale notes have consecutive letters so the interval must be called a 2nd but it is 1 semitone larger than a major 2nd. In other words, it’s an augmented 2nd.

We can’t call F – G# a minor 3rd because then G# would have to be renamed as Ab, implying that there is a possible scale note in between, F – G – Ab.
The difference between a minor 3rd and an augmented 2nd is quite noticeable when hearing the same pitches in different contexts.

Key Signature Shortcut

To this day, the melodic and harmonic minors are more popular in most genres than the natural minor. Since both involve the use of accidentals, either on the 6th and 7th note or just the 7th note, the frequent or early presence of an accidental in the part would likely indicate that the piece is in a minor key.
A key signature can equally represent a major and a minor key. Usually we look for clues in the first and last bars to find the root note, so we know whether the key signature represents the major or minor key for that key signature.
If there’s a recurring accidental, the piece is probably in the minor key of that key signature.

You can check this by seeing if the accidental is the 6th or 7th note of the key signature’s minor key.

For example, in the key signature of 1 sharp (F#), the key could be G major or E minor. If the part contains a C# or D# in the first few bars, the piece is most likely in E minor rather than G major.

Sing Along

Almost all voices and pitched instruments can sing or play one octave starting on C. Listen to all three minors on C and compare their character. Learn to sing and play all three.