I've been playing French Horn for 20 years, and thought I had most basic concepts regarding accidentals understood. But the other day I came across the following image via Wikipedia, which had me questioning what I thought I knew:


Wikipedia source

I see octave jumps quite often in the pieces that I play, and sometimes they have the lower note with an accidental, as the image illustrates.

However, I've always thought that an accidental on a lower octave would also be applied to the upper octave.

I don't recall any strange dissonance when playing it that way, though.

Is the wiki page correct? Have I been playing them wrong all of these years?


9 Answers 9


Wikipedia has it right. An accidental that is written in, as shown in the example above, only applies to the note in that octave until the end of the measure.

You may be confusing it with the sharps and flats in the key signature which do apply to every octave. It's also possible that in the pieces you are playing you are seeing a courtesy accidental instead of an actual accidental. Courtesy accidental are unnecessary, but are typically deemed helpful for the reader.

  • 3
    Very strange - I've always been under the impression that it applied to all octaves. Thanks for the clarification!
    – Siyual
    Commented Oct 20, 2016 at 14:32
  • 11
    Old French music used to apply accidentals to all octaves, and occasionally you'll find an old edition that hasn't been re-edited, but this is rare.
    – MattPutnam
    Commented Oct 20, 2016 at 15:56
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    In general, with original manuscripts and published editions of "old music" (e.g. before about 1750) , you first have to figure out what convention was actually being used for accidentals (there were several different ones in use), and then figure out how carefully, or not, the copyist or engraver actually followed their chosen convention!
    – user19146
    Commented Oct 20, 2016 at 20:51
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    @Siyual I have seen scores of choir music where accidentals were applied to all octaves, but only of the voice where that accidental was, other voices were unaffected despite being written on the same staff. Again, in another score accidentals applied only to the nearest note, but at least there was editor's note (which was great because it would be impossible to check by ear with so many dissonances).
    – dtldarek
    Commented Oct 20, 2016 at 21:33
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    @dtldarek That's slightly unusual. What's usual is that different voices in the same staff are accidented independently if they are played by different instruments. This is even true in some scores for piano pieces if both hands are written in one staff for a part of the piece.
    – yo'
    Commented Oct 21, 2016 at 4:25

The book "Behind Bars: The Definitive Guide to Music Notation", by Elaine Gould (Published Faber Music, 2011) states:

An accidental holds good for the duration of a bar. It applies only to the pitch at which it is written: each additional octave requires a further accidental. (p.78.)

  • This appears to conflict with the answers on music.stackexchange.com/questions/108312/… and music.stackexchange.com/questions/107706/… , which suggest that accidentals are connected to a certain line or space on the staff, not a certain pitch. Edit: I see this has already been pointed out on one of the answers which I linked
    – Edward
    Commented Dec 5, 2021 at 19:28
  • While I was practicing Etude 1 of Marcel Mule's 18 exercises, I stumbled upon this issue in Measure 10 (that brought me here). See the screenshot here: i.imgur.com/tbnTqck.jpg . I am not sure if the higher E should also be a flat or is it natural. In this Youtube video, the player clearly played a flat for that higher octave E: youtu.be/GxbQ7i2qgkw . This also conflicts with Elaine Gould. Commented Oct 18, 2022 at 2:01

An accidental in a different octave in the same instrument is usually explicitly disambiguated in order to spare the player from figuring out whether it may or may not apply. If not, it is usually held that the accidental from the different octave does not apply.

  • 5
    I just realized the irony in how confusing the word "disambiguated" can be.
    – Richard
    Commented Oct 20, 2016 at 18:14
  • 6
    @Richard so.. you're trying to undisambiguate its meaning? Commented Oct 21, 2016 at 11:17
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    @CarlWitthoft At the risk of de-undisambiguating it, yes.
    – Richard
    Commented Oct 21, 2016 at 13:39

If a stacked chord is shown with the same note appearing in more than one octave and only one carries an accidental it kind of would make sense to 'play the note as seen' that is, not with the accidental.But he very reason for an accidental to apply to the duration of a bar is harmonic. The bar is deemed to be 'in that harmonic state' therefore for an accidental NOT to apply to other octaves in a melody is just bizzare. Jazz practice always applies accidentals to all octaves as far as I am aware.

This goes to show how unacceptable the state of contemporary music theory and common practice is. IMO all accidentals should be marked UNLESS they are consecutive. Just try asking for the meaning of 'Andantino'.

  • One could possibly argue that because the harmonic series itself spans multiple octaves, the harmonic state also refers to the state of all octaves and not just one. I've seen both conventions used regarding accidentals spanning octaves and share user34117's experience that explicit disambiguation is the generally preferred strategy. Commented Mar 6, 2018 at 17:02

I have a 1936 edition of V. Cornerre's method and the the edition only marks the first accidental in a bar but clearly applies to all octaves, such as the octave jump exercises. However, I have numerous other pieces that don't apply the accidental to octaves. Conclusion, you have to figure out the harmonic intent.


I've always played where accidentals only carry thru to notes of the same octave, but I'm working out of a jazz book on walking bass lines and some of it would make more harmonic sense if the accidentals carried thru to other octaves with the way that it's written, the book is called Modern Walking Bass Technique and there's a note in the beginning saying that accidentals carry thru to all octaves of the bar! I haven't seen this before.


My Berklee College of Music instructor says that in classical music, an accidental does not carry through to other octaves, but in jazz it does.

  • 1
    This seems to corroborate Kevin's and user46131's answer. Commented Sep 27, 2019 at 3:22

In Bar 21 of Chopin's waltz in A minor the 8th note in the right hand is an interesting case in that it is a G at the start of an octave higher section which is clearly intended to be a G♯, as the previous occurrence of the note at that position in the stave but not an octave higher - and all the other Gs in the bar - are sharp, but arguably it should have an accidental as it is not the same G.

  • Are we talking about Brown-Index 150? If so, the manuscript does have a sharp sign on that G. Perhaps the editor of your edition forgot it, but Chopin didn't. Nor do any of the urtext editions I've seen put that sharp sign in brackets to show it was omitted.
    – DjinTonic
    Commented Feb 11 at 23:43

Sort of, depends on the mode. Assuming this is Ionian mode, the piece has no key signature, so the accidental F# applies to all F# in that bar - regardless of the octave. It should be: Bar 1: F#, F#, F# Bar 2: F (natural, as it's the beginning of a new bar/measure), F#, F#

If they wanted to you to play it as written, then the natural sign would be placed against the appropriate note.

  • 6
    This is inaccurate and untrue.
    – Tim
    Commented Oct 21, 2016 at 8:13
  • As far as I am aware, the only time a accidental applies to all octaves is when it's placed in the key signature. Commented Mar 8, 2018 at 20:21

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