If we are playing music and we hear someone ask, “What are accidentals in music?” they do not mean mistakes. Neither do they mean there is something recently discovered that is wrong with the music.
When we play our music, we play in a key. The key has what we call a key signature. This tells us if any of the notes should be played sharp (#) or flat (b). This will usually apply to the piece from start to finish. Although there are occasions where you might get a key change.
In the key of C, our scale notes are C – D – E – F – G – A – B and C. No sharps and flats. If we play in the key of G, the notes will be G – A – B – C – D – E – F# and G. Just one sharp. But what do we do if we want to play a note that is not included in our scale? We need to be able to write it down. Accidentals allow us to do that.
An Accidental is…
This simplest definition of an accidental is a note that is not part of the scale of the key signature you are using. We identify it by using a sharp (#), flat (b), or natural (♮). Those are the symbols for accidentals in music. They are how we write our music in notation form.
We are all aware of what they do. The sharp will raise the note by a half step or semitone; the flat will lower it by the same amount. The natural will either lower or raise the note depending on the note as defined in the key signature. However, this is not a permanent arrangement for playing that note, just temporary. We will define how that works later.
Why Use Accidentals?
Having identified that they just lower or raise the note temporarily, why bother? We don’t have to use them; they are not compulsory. But in a way, we do.
How boring would music be without them? Used to good effect, they will give you subtle changes to the sound of the music that just makes it more interesting. Playing just the seven different notes in the scale would become very mundane and uninspiring.
Using notes that are outside of the scale or the key set adds interest and change. That is the main benefit of using accidentals in music. So, let’s look at how this can work…
Basic Examples of Accidentals
Let’s assume we are playing in the key of G major. We have already looked at what the notes of the scale are, but let’s remind ourselves. They are G – A – B – C – D – E – F# and G.
As we can see, there is just one sharp, on the “F” or top line of the stave. This tells us that every time we play an F, then we actually play an F sharp.
But what if we didn’t want to do that? What if we wanted to play an F instead of the F#? In that case, we would place the Natural sign (♮) in front of the note on the stave line. This tells us that the note is not F sharp but F. Effectively overriding the formal key set note.
Let’s look at another example
Our third note in the scale of G is a B. What if we wanted to play a Bb. Then we simply place the flat sign (b) in front of the note on the stave line. That overrides the B that is in scale and gives us the B flat we want.
The same principle would apply to a sharp. These symbols are known as accidentals. But to make life more interesting, or otherwise, there are a couple of rules. Music Theory people live by their rules, and of course, the exceptions to them. These rules will apply not only to the note that the accidental is applied to but can affect other notes as well.
The First Rule
Consider that the music is divided strictly into bars. If you apply an accidental sharp to a note in the bar, it applies to the same note anywhere else in the bar.
Continuing with the scale of G, if the third note of B has a flat applied, the same flat will apply to any other B in that bar. However, that doesn’t apply to a B that is an octave lower or higher.
An accidental only lasts for the bar it is in
If you need to apply the same accidental in the next bar, you will have to apply it again. The accidental will last for the bar. What if the note is repeated, but you do not want the sharp or flat you applied? In that case, you will have to apply another accidental to cancel it for the latter note.
The Second Rule
We have already touched on this under the first rule heading. The second rule of accidental in music is that it does not carry on into the next bar. Once you cross the bar line to the next bar or measure, the accidentals don’t exist anymore. The notes then revert to the scales in the key signature you are using. If they are required, they will have to be applied again.
Are there exceptions to the rules?
Of course, there are. When people make rules, it feels like there are always ways to create exceptions. Accidentals are no exception.
Accidentals with Tied Notes
When two notes are “tied” over the bar line, then the accidental will still apply, even though you have moved into the following bar when it should revert to the original key.
Tied notes are notes that are the same and played consecutively but cross the bar line. It’s an exception that makes sense. It means you haven’t got to apply another accidental at the start of the new bar. However, when the same note appears again in the bar, you will have to apply an accidental.
In the key of G, you have your flattened third of B, making Bb. If it is tied, then the B note stays as Bb flat into the next bar. There might, however, be another B to B flat required in that next bar. If so, you will have to apply the accidental flat symbol again.
To finish answering the question, “What are accidentals in music?” I need to quickly mention the Double accidentals. I don’t need to spend too much time on these as they are rarely seen. It simply means that two accidentals are applied.
This has the effect of either raising or lowering the note by two semitones or a full step. Double accidental sharps are given the symbol ‘X.’ Double accidental flats are given a ‘bb’ symbol.
As an example…
A double sharp accidental for the note of D would make it an E. But ‘Dx’ would be enharmonically equivalent, or the same, as an E natural, as we just said. So why not just write it as E.
You might catch them in key signatures with lots of sharp or flats. In the key of C#, for instance, but that is probably going to be the only time.
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What Are Accidentals In Music – Final Thoughts
A lot of people ask, “When do you use an Accidental in music?” I am going to stick my neck out here and say when you feel like it. There aren’t any rules I am aware of that say you can’t use it here or must use it there. Whatever feels right in the music is probably right.
If you would like some detailed guides on accidentals in music, some further reading on the subject is Why Scales Need Sharps and Flats: Notes on Music Theory and How to Read Music: Fundamentals of Music Notation Made Easy.
Sometimes a good way to practice these things is to write them down, and some manuscript paper, such as the Music Manuscript Notebook, is going to be useful.
Until next time, let the music play.