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key signatures and accidentals

Active Member
Joined: 13 years ago
Posts: 5
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Fairly new to music reading. I know how to interpret key signatures and I know how to interpret accidentals. I'm confused about how to deal with it when they are together.

For example, if a key signature shows all C's to be sharp, how do you interpret a note of C with a sharp accidental? Would it be a double sharp?, Basically does one take precendence over the other or does it just add to it. And would the accidental affect every C (as a key signature does), or just that particular note.

As you can tell, I'm a bit confused


Famed Member
Joined: 18 years ago
Posts: 4933

A double sharp is indicated with an x in front of the note.

There are two instances where you'll see the same sharp in a key signature and as an accidental within a measure in 'standard' notation:

1. If the note has already been altered with a natural, an accidental must be used to return it to the normal (key signature) pitch within the same measure

2. In beginner pieces and method books, it is common for publishers to use "courtesy" accidentals - reminders that the note is sharp. These will typically occur after a note was altered in the previous measure. Even though the note would be C# anyway (because the barline 'resets' things to the key signature), it's there as a reminder.

There's also a non-standard situation, but it'll only apply if you're reading music originally written for the harp. Because of the way a harp works, performers find it convenient to NOT 'reset' accidentals at bar lines. So if there's a C natural in any measure, all the following C notes are also natural - until you hit a different accidental. This system is called Salzedo notation after its creator, but I've never seen it used outside of harp music.

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