I am working through my grade 1 theory book and am a little confused on a question. I have learnt that you either use key signatures or accidentals when writing out a scale. Not both.

The question I have is asking me to write a descending F major scale on the bass clef but the B flat note is on a ledger line. Do I put an accidental in front of it or not?enter image description here


  • As soon as you get into harmonic and melodic minors, you have to use both key sig and accidentals! Sorry!
    – Tim
    Feb 9, 2017 at 8:36
  • Not sure that would be marked correct. Once a key sig is stated, there's no need to write in the accidental for the affected note/s. They're already flattened. At grade I it'll probably be allowed, but please check with teacher. Your 1st para. alludes to that.
    – Tim
    Feb 9, 2017 at 8:40
  • In all the theory methods I have done in the last four years both British and South African none would want you to repeat the key signature like that.
    – Neil Meyer
    Feb 9, 2017 at 16:24
  • You can be glad I'm not your teacher otherwise I'd make you write than again (-;
    – Neil Meyer
    Feb 9, 2017 at 16:37
  • @NeilMeyer - by 'initial' do you mean 'write an accidental'?
    – Tim
    Feb 9, 2017 at 16:39

1 Answer 1


When it comes to key signatures, the accidentals given apply to ALL of those notes, no matter the register. Thus ALL Bs will become B-flats with the given key signature, and so you don't need to add in that accidental.

(Interestingly, this is not true of lone accidentals! They only apply to that particular pitch in that particular register.)

And one last bit. You said:

I have learnt that you either use key signatures or accidentals when writing out a scale. Not both.

Later on, you'll learn that sometimes you'll need key signatures and accidentals. So just know that that's possible in the future!

  • Wish there was a term for the # and b in the key sig. 'cos they're hardly accidentals, are they?
    – Tim
    Feb 9, 2017 at 8:35
  • @Tim I'd say they are just "sharp symbols" and "flat symbols". I agree that "accidentals in the key signature" doesn't make much sense, because "accidental" refers to it being outside the key signature.
    – IMSoP
    Feb 9, 2017 at 13:09
  • Also worth noting: Accidentals within a measure apply to all notes of that pitch in that measure, unless explicitly canceled out by another accidental or the natural. (Is that what was meant by your parenthetical?) Feb 9, 2017 at 16:31
  • In parentheses, I meant that accidentals only apply to that pitch, not to that pitch class, but I was weary of using that terminology. Feb 9, 2017 at 16:33

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