A blog about music theory demystified. Music theory and notation made simple. A holistic approach to understanding music theory. Free basic music theory lessons. Online music theory books.
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.
If you found this post helpful, please feel welcome to like, share or leave a comment. If you have any questions, leave them as a comment and I’ll respond as soon as I can. To stay up to date with new posts, please subscribe.
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.
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.
Once you’ve learnt these, try singing or playing them in different keys (on different root notes).
If you found this post helpful, please feel welcome to like, share or leave a comment. If you have any questions, leave them as a comment and I’ll respond as soon as I can. To stay up to date with new posts, please subscribe.
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 chromatic scale
The chromatic scale is made up of every one of the 12 musical note pitches, each 1 semitone apart from the next. It is the parent of all modes (…except in cultures with more than 12 note pitches per octave…).
Apart from some largely academic genres such as serial music, chromatic scales are mainly used as musical effects, such as the rapid chromatic passages used to build tension and drama in film music.
As a key, the chromatic scale has no inherent tonality: there’s no way to tell the root note from any other note. That’s not to say that you can’t nominate a root note, just that it requires a lot of effort to make that root note felt in a piece.
I don’t mean that it has no musical character, either. It does, but it’s a very nebulous one…
Modes
A mode is the pattern of intervals that determines which of the 12 different note pitches within an octave are used to produce a scale/key. Apart from the chromatic scale and the “whole tone scale” (6 notes within an octave, with 2 semitones between each note and the next), modes have an irregular pattern to their interval structure. As long as the root note is highlighted from time to time this irregularity allows a mode’s unique character to permeate the character of the music.
Diatonic Modes
The traditional Western modes, such as ionian (major) and aeolian (minor), are made up of one- and two-semitone intervals. Such modes are called diatonic modes; modes whose scales only have two different size intervals between their notes.
Just to be confusing, they’re also called heptatonic modes, meaning that they have 7 different notes within an octave. The traditional modes are all made up of 7 different notes, where the eighth note is the octave of the first.
A mode doesn’t innately have these limits. For example, the harmonic minor (discussed later in this course) still has 7 notes but one of its intervals is 3 semitones, that between the 6th and 7th notes of the scale. Other modes have a different number of notes per octave, such as pentatonic (5-note) modes and the blues mode. Some modes even use one or more different notes ascending and descending. The melodic minor works like that, as do some Indian modes.
However, the most common modes in most Western genres are the traditional Western modes which evolved out of the Renaissance era.
Although often associated with period music and traditional folk music, some modes, such as the myxolydian mode, are commonly used in a variety of other genres. Jazz goes even further by using relative modes as an approach to improvising around extended chords.
What Are The Traditional Modes?
Let’s have a look at the natural notes for two octaves. Each note can be the root note of a diatonic mode (yeah, I wouldn’t worry about the “heptatonic” bit, it seldom crops up in conversation…).
The traditional Western modes
Look at the notes for an octave, starting on each note in turn. Each root note produces a different pattern: a different mode.
We can compare their interval structure by lining them up underneath each other.
Each different mode has a unique quality that greatly influences the overall character of music played in that mode.
You can hear this, even by just playing a scale.
You can also teach yourself a new mode just by reading and playing the notes of the scale.
If you play by ear, follow its pattern of intervals on your instrument by counting semitones.
Below is a scale of each mode starting on A, so we can compare their character..
A aeolian (natural minor)
A locrian
A ionian (major)
A dorian
A phrygian
A lydian
A myxolydian
The character of each mode is easy to identify in a melody. Have a listen to this short, simple melody played in each of the modes…
Simple melody in A aeolian (natural minor)
Simple melody in A locrian
Simple melody in A ionian (major)
Simple melody in A dorian
Simple melody in A phrygian
Simple melody in A lydian
Simple melody in A myxolydian
Modes And Key Signatures
The way in which key signatures are used for modes other than major or minor depends on genre and school. There are two approaches: like major/like minor or the mode’s actual key signature.
Like Major or Like Minor
Classical musicians are brought up on a strict diet of major and minor (as well as two variations of the minor, melodic minor and harmonic minor). A classically trained player is only going to look for two possible root notes when interpreting a key signature. Music in a less familiar mode would be hard to interpret on first reading; the root note would seem to conflict with the key signature.
The most important notes of a scale are the root note and the note 7 semitones above the root note, called a perfect 5th (don’t worry about the interval name, we’ll look at interval names soon). The perfect 5th helps stabilise the root note.
There is one other important note, the 3rd note. One reason the 3rd is important is because it’s the most significant difference between major and minor. In the major mode the 3rd note is 4 semitones above the root note and in the minor it’s 3 semitones above the root note.
We can categorise the other modes as being “like major” or “like minor”, based on the 3rd note.
Below is a list of the modes staring on A, grouped in “like major” or “like minor”. The note in the other modes that differs from the major or minor is highlighted.
Note that the locrian mode is not in either list! The locrian mode wasn’t used in Western music, or even named, until relatively recently because it lacks the essential ingredient of a perfect 5th. By not having a note 7 semitones above the root note, music written in this mode is elusive. We naturally listen for a root note but we either can’t find it or we’re misled by other possible root notes that do have a perfect 5th but don’t hang around long enough to feel convincing.
It’s VERY hard to make the root note stick in the locrian mode. Modes without a perfect 5th need almost constant reinforcement of the root note in order to be musically stable. One way to achieve this is by having a drone accompaniment, where the root note persists throughout the piece.
Accidentals
For modes which are like major, we use the key signature of the parallel major mode; the major mode on the same root note.
For modes which are like minor, we use the key signature of the parallel minor mode; the minor mode with the same root note.
This requires the use of an accidental. Anyone who’s seen music written in the melodic or harmonic minor will be used to accidentals used in this way.
For example, let’s look at one of the more common modes, the myxolydian mode.
Using only naturals (key signature of 0 sharps/flats), the myxolydian mode starts on G. The actual key signature of G myxolydian is 0 sharps/flats.
The myxolydian mode is like major, so for a ”like major/like minor” key signature we would use the key signature of the major mode on G, G major, which is 1 sharp (F#).
To preserve the intervals of the myxolydian mode we need to flatten the 7th note, the note which differs from the major of the same root note, F# (remember, in the cycle of 5ths, the latest sharp is the 7th note of the scale…).
When we flatten F# we get F natural, so for the first F in every bar that has one, we write a natural sign as an accidental.
*NOTE: An accidental is only written for the first instance of a given note in each bar.
Try These…
Like Major, Like Minor
Write the scale of the following modes for 1 octave ascending using the key signature of its parallel major or minor (the major or minor key with the same root note) and an accidental where required. Base your decision on whether the 3rd note belongs to the parallel major or parallel minor.
NOTE: Accidentals aren’t written as part of the key signature. They must be written beside the first instance of that note in every bar where that note occurs.
A dorian
D lydian
C ionian (trick question… just seeing if you were paying attention)
C myxolydian
B phrygian
F# dorian
Bb myxolydian
Answers at the end of this post.
Actual Key Signature
Players of early music and traditional folk music, as well as a number of other genres, are quite familiar with the traditional modes. Typically, in such genres the actual key signature is used.
In the above example, G myxolydian is written in the key signature of 0 sharps/flats, rather than in the key of G major with F natural as an accidental. It’s cleaner and simpler to read (as long as you interpret the key signature correctly when reading).
When first reading a piece knowing only it’s key signature, you might wonder how to determine the root note of the piece, with so many modes to choose from. The approach is the same as when you’re just looking for major or minor. Look for an obvious note near the start and end of the piece.
Pentatonic modes (5 notes per octave) are quite popular in various genres. Having only 5 notes, we can think of them as a subset of the traditional heptatonic modes that we’ve already looked at.
The most well known of these is the minor pentatonic mode, notes 1, 3, 4, 5 and 7 of the natural minor/aeolian mode. In this instance, we would use the key signature of the “parent” minor key. Other Western pentatonic modes are also subsets of parent modes, so we would use the key signature of the “like major” or “like minor” mode of which it is a subset.
Here are the two most common Western pentatonic modes.
Not all pentatonic modes are related to a parent Western mode. Any combination of 5 notes within an octave can be used as a pentatonic mode.
The Blues Scale
The most common mode in blues is a hexatonic (6-note) mode based on the minor pentatonic, with an extra note added between the 4th and 5th notes. From a notation viewpoint, there is no room in the naming system for the extra note to have its own letter: instead, it is considered an alternative to the 4th or 5th note and should be named according to its use. Either option requires an accidental.
Other Modes
Most musical cultures around the world have a concept of modes, a system of choosing a set of notes within an octave based on a root note and the intervals between its scale notes. Some use different intonation (tuning) systems: such modes can sound unfamiliar to the Western ear. Many are based on the same intonation as Western music, 12-Tone Equal Temperament, yet may have different numbers of notes per octave or notes that differ when ascending or descending. If you wish to experiment, you can create your own mode for a new composition or improvisation.
Freedom From Modes
The Western modes were originally used as a rigid framework for determining which notes were used in a composition. Over time, as music developed towards the journey through various visiting keys that it largely is today, the use of accidentals became more and more common, to accommodate these temporary keys.
Accidentals are also used for embellishment (ornamentation). Ornaments are treated as effects: an ornament may well use notes outside the key, requiring an accidental. This may extend to chromatic passages involving several accidentals.
The contemporary view is that a key is based on the overall use of the notes of a major or minor key, with the option of sharpening/flattening notes or incorporating other notes as desired.
If you found this post helpful, please feel welcome to like, share or leave a comment. If you have any questions, leave them as a comment and I’ll respond as soon as I can. To stay up to date wth new posts, please subscribe.
