An Introduction to the Double Sharp
If you’ve spent some time digging deep into music theory, you may have encountered something unusual: the double sharp.
You know what a sharp is, so you’re a little fuzzy on what a double sharp is supposed to be. Or, maybe you don’t know what a sharp is either and you’re just through-and-through confused.
Either way, we’ve got your back. Keep reading for a comprehensive explanation of what a double sharp is, how it works, why you need it, and how to work with it in music.
Understanding the Double Sharp
In order to fully understand what a double sharp is, you first need to understand what a sharp is.
Let’s break it down.
Sharps and Flats: What are They?
If you’ve spent any time looking at a piano keyboard and reading basic sheet music, then you’re probably familiar with the white keys, also known as the natural notes.
These notes are named for the Latin alphabet: A, B, C, D, E, F, G. All of the white keys on a piano keyboard are considered natural notes.
Then, there are the black keys. These are your sharps and flats.
Sharps and flats are two types of accidentals used to raise or lower a pitch by a half step. The sharp symbol in sheet music is #, while the flat symbol looks like a lowercase b.
So, when you want to raise a pitch by a half step, you’re sharpening it. For example, let’s say you want to raise D by a half step. This would be D#, the black key immediately to the right of D.
What is a Double Sharp?
This brings us to the double sharp.
If a sharp raises a note by a half step, it makes sense that a double sharp raises a note by two half steps or a whole tone.
So, if you wanted to play a double sharp for D, you would play the white key E, as this is two half steps away.
A double sharp is noted on sheet music in one of two ways: as either ## or as an x. So, if you encountered Cx, you would be playing a double sharp of C, or D.
While single sharps often indicate black keys (but not always, as in the case of E# or B#), double sharps often indicate white or natural keys. A#, for example, is a black key, while Ax is a white key (B).
Why Do We Need Double Sharp and Flat Signs?
All of this begs the question: Why go to so much trouble with double sharps if you could just write the next note up?
In fact, double sharps (and other double accidentals) are not seen in any working key signature. If anything, certain double sharp scenarios belong under the purview of theoretical key signatures.
That said, the purpose of double sharps is actually quite simple. It’s best illustrated by looking at a scale with a lot of sharps, like F# major, to illustrate why we use sharps.
The notes of F# major are F#, G#, A#, B, C#, D#, E#, F#.
If you’re paying attention, you’ll remember something we mentioned earlier: Sharps often denote black keys, but not always. One of the instances they don’t denote black keys is E#, which is actually just F.
So, why write E# when we could just write F?
It’s simple. By naming E# as F in the scale, we would be missing the whole point of having a scale that moves in melodic steps. If we read D#, F, F#, we would get the idea that we jumped two whole steps from D# to F, which is incorrect for the pattern of the scale.
With that in mind, let’s take a look at the original question: Why do you need a double sharp?
To answer that, let’s look at a scale that contains a double sharp, G# major.
The notes of G# major are G#, A#, B#, C#, D#, E#, F##, G#.
Technically speaking, it’s simpler to write G than F##, but a composer would never write it this way.
That’s because the same logic applies. Without the double sharp, the scale would be written as G#, A#, B#, C#, D#, E#, G, G#, which reads as a misrepresentation of the scale formula.
Canceling a Double Sharp
Now, let’s say you’re feeling wild and want to cancel a double sharp for some reason. There are a couple different ways you can do this.
First, it depends on whether you want the note to revert to a regular sharp or to its natural state.
If you want a double sharp to revert to a single sharp, simply place a single sharp simple in front of the double sharp sign.
If you want a double sharp to revert to a natural note, simply place a natural sign in front of the double sharp sign.
Playing Beyond Sharps and Flats
Think you’re ready to conquer the double sharp?
If you’re still unsure, no worries. You’ve come to the right place.
We’re here to help you with all stages of your piano learning journey, whether you’re a brand new player or a seasoned concert pianist.
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