I am hoping to enter the music in the attached image into a midi sequencing program. enter image description here

The problem I'm having is understanding the musical notation here. Traditionally, accidentals follow pretty basic rules, at least according to the wikipedia article on musical accidentals:

Accidentals apply within the measure and octave in which they appear, unless canceled by another accidental sign, or tied into the following measure. If a note has an accidental and the note is repeated in a different octave within the same measure, the accidental does not apply to the same note of the different octave.

It adds:

Accidentals apply to subsequent notes on the same staff position for the remainder of the measure where they occur, unless explicitly changed by another accidental. Once a barline is passed, the effect of the accidental ends, except when a note affected by an accidental is tied to the same note across a barline. Subsequent notes at the same staff position in the second or later bars are not affected by the accidental carried through with the tied note.

However, citing Kurt Stone, the wikipedia article also describes a more modern approach to accidentals that is said to be used in modern scores (of which the aforementioned music is an example) that has a different set of rules which provides some advantages of compactness in atonal music. I suspect these rules apply to the music I'm working on:

1 - Accidentals affect only those notes which they immediately precede.

2 - Accidentals are not repeated on tied notes unless the tie goes from line to line or page to page.

3 - Accidentals are not repeated for repeated notes unless one or more different pitches (or rests) intervene.

4 - If a sharp or flat pitch is followed directly by its natural form, a natural is used.

5 - Courtesy accidentals or naturals (in parentheses) may be used to clarify ambiguities but are kept to a minimum

I'm hoping I can get some questions answered:

A) In the first instrument, the horns, at the top, why is there a natural (♮) on that first note in the bass? It's the very first note with no key signature, why do need to make it natural? Is this a courtesy accidental?

B) In the second instrument (oboes, clarinets, etc.) in the second measure has two sharps on each of those first two notes (presumably because they are separate instruments) and then no other accidentals for the rest of the measure. Does that mean the other notes are just C instead of C♯? Or are all those notes in that second measure C♯? This happens again in the third measure, which has a natural on the C an octave up.  Generally confused about which notes are C and which are C♯ here.

C) Referring again to the oboes/clarinets third measure, If we have one accidental, say a sharp on the low octave to make it C♯, then we have a natural on the C an octave higher for the next note, does that mean that any C after that natural is natural unless it specifically has an accidental?

D) To solidify my grasp on this, can someone confirm that I have the right notes for the oboes/clarinets instruments here:

C# C# C# **C** C# C# C# C#
all notes C#
same as measure 1
all notes C#
same as measure 1
all notes C#

I'd greatly appreciate any assistance in understanding the use of accidentals here.

  • 1
    @Tim There's no need for the #, but if it wasn't there there's a good chance somebody would either play it wrongly or interrupt a rehearsal to ask about it
    – PiedPiper
    Oct 5, 2019 at 10:22
  • 1
    @PiedPiper - maybe. So why isn't it also in the previous bar, and the one 3 bars earlier? I like uniformity, and it ain't here!
    – Tim
    Oct 5, 2019 at 11:44
  • 1
    @tim i believe the # you refer to in mid measure at 2:08 is there because of rule 3 Accidentals are not repeated for repeated notes unless one or more different pitches (or rests) intervene
    – S. Imp
    Oct 5, 2019 at 15:55
  • 1
    @Dekkadeci it's from the Battle of Hoth by John Williams. This particular bit occurs at about 6:04
    – S. Imp
    Oct 5, 2019 at 15:57
  • 1
    @S.Imp - to me that 'logic' says that a. if there's a rest - so what (rests don't need accidentals!) and b. 'immediate' - so every other C(#) needs an accidental. This seems like bureacracy gone mad - again. 'If it ain't broke...' It's worked for a fair amount of time with few problems - if any. But we have to change, don't we..?! I'm now going back under my stone.
    – Tim
    Oct 5, 2019 at 16:22

4 Answers 4


This piece is using the traditional rules for accidentals, plus adding some courtesy accidentals for disambiguation. A lot of people are unsure about the rules and think that an accidental in one octave also applies to notes in other octaves. Adding courtesy accidentals on the same note in other octaves makes the intention explicit (e.g. 1st measure oboes/clarinets).

To answer your specific questions:

  • A) The natural is unnecessary. There were very probably A-flats in the horns in previous measures and this is a courtesy accidental.
  • B) In the oboes and clarinets all of the lower notes are C-sharps. The C-natural in the upper is a courtesy accidental to make sure there is no confusion. The first C-sharp is repeated because two players would be playing the part and each player sees the accidentals they need without having to read the other part as well. The third C-sharp in M1 is also a courtesy accidental to make sure nobody thinks the C-natural applies to those notes.
  • C) M3 is the same as M1: all of the lower notes are C-sharps (following the traditional rules)
  • D) Yes, you've understood this correctly

Atonal pieces that use the modern conventions usually state explicitly at the top that they are using these conventions.
And also note that even if you were to apply the modern conventions for accidentals then the oboe/clarinet notes would still be C-sharps because an accidental carries over to repeated notes (rule 3).

  • thanks for your detailed answer here. It was the presence of the courtesy accidentals (and the atonal/modern nature of the piece) which made me think this was using the modern rules for accidentals, but upon further rumination, I think I agree that the traditional rules and the modern rules might in fact both yield the exact same interpretation here. The score reduction makes no mention of which convention is used.
    – S. Imp
    Oct 5, 2019 at 16:20
  • Film music almost always uses the traditional notation
    – PiedPiper
    Oct 5, 2019 at 16:44
  • It's not using the traditional rules for accidentals to the extent that the courtesy accidentals are not in parentheses.
    – phoog
    Oct 6, 2019 at 20:08
  • @phoog There's absolutely no need to put courtesy accidentals in parentheses. In fact it just clutters the layout unnecessarily.
    – PiedPiper
    Oct 6, 2019 at 21:08
  • @PiedPiper yet it is the tradition to do so. And I find that it is indeed useful: without the parentheses, unnecessary accidentals can cause confusion, when the reader wonders what was missed.
    – phoog
    Oct 6, 2019 at 22:10

These are almost certainly cautionary accidentals.

When several different parts are written on one staff, it is common to supply all the accidentals required for each part, because if the clarinet (for example) was playing from this sheet music, he/she would be paying more attention to his/her own notes than trying to read everything else as well.

There are many different conventions about adding cautionary accidentals, used by different music publishers and/or in different styles of music. Here are a selection of the options for cautionaries that are generated automatically in one computer notation program (and in total there are more than twenty different groups of options, not just the ones show below).

enter image description here


A) I think you're correct.

In your B), you write "In the second instrument (oboes, clarinets, etc.) in the second measure has two sharps on each of those first two notes (presumably because they are separate instruments)". This is correct. It's so that two players can read from the same part, and each player sees all the accidentals they need to see, even if they ignore the other player's notes.

As to the clarinets in b.2, all notes are indeed C♯ as your table says.

It is true that there are some needless accidentals. But I don't see this as evidence that the composer has adopted a modern practice of making each accidental apply only to the note it's next to. In any case, for b.2's last 6 notes to be C natural, the composer would have to not just adopt that modern practice but also go against Kurt Stone's rule 3 which you quote. The piano right hand shows a similar phenomenon -- repeated chords, but the accidentals are renewed only on the first chord after the bar line.

C) The natural on the high C does not affect the low Cs (C sharps). I expect that that natural is a courtesy accidental. (I think that if I were notating this, I'd choose to spell the C sharps as D flats, but perhaps there's some good reason to mix Cs and C sharps here.)

  • I appreciate your answer for A, but for B you didn't answer the question as to what the notes are. I've edited my question to ask the question more explicitly. Thank you for your answer for C also.
    – S. Imp
    Oct 5, 2019 at 6:27

There are some situations where an accidental should be printed in front of a note regardless of whether it is sharp, flat, or natural. A couple of principles to consider:

  1. In many genres of music, printing mistakes are more common than augmented or diminished octaves. While an accidental applied to one note doesn't apply to the same letter note in other octaves, a note which appears without an accidental while a note an octave away has an accidental may be viewed by readers as a potential printing mistake. Using e.g. a sharp on one and a natural on the other will make the intention obvious.

  2. Different parts may sometimes be played by different people, and sometimes by the same person. If in C major, e.g. a soprano sings a B-flat accidental early in a measure, and an alto sings an unmarked B later in the measure, an alto singer who wasn't looking at the soprano part would sing the note as B natural, but a keyboard player who is trying to perform both parts would likely play it as B flat. Similar situations may arise with two flute parts printed on a staff for performance by two flute players or one keyboardist.

Although one could write rules which unambiguously characterized every unnmarked note as altered or unaltered, I think it is more useful to recognize that in some cases an unmarked note won't be read reliably as either, thus necessitating an accidental in any case.

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