Are key signatures sharps and flats the same as passing tones?

Lets say you're playing in the key of C. No flats or sharps.

The next key up is G because, harmonically speaking, G is the closest note to C (it has the most similar tone quality ... do re mi fa so ..do and so...the fifth).

G, the key of, has an F#. Is that F# also considered a 'passing tone' in C? That is, a non-scale tone that's harmonically related as it's coming from the next key up?

Similarly would Bb (B-flat, A#) be another passing tone (or some other name for it?) as it's coming from the key of F which is the next 'lower' key from C?

And so on ... the next passing tones would be two keys away (F# and C# if you go up again to the key of D ... and B-Flat and E-flat going down).

  • 1
    Clarifying terms: "accidentals" means "notes not belonging to the key you're currently in." It's not synonymous with "sharps and flats"; thus, the F# in the key signature of G major is not an accidental; it's just a sharp. Aug 17, 2021 at 17:00
  • 1
    Reality - sharps and flats in any key signature are NOT accidentals! Accidentals are the sharps/flats/naturals that occur in any keys to denote (sic) any non-diatonic notes. So the premise that the question is asked on is faulty. Sorry!
    – Tim
    Aug 17, 2021 at 17:09
  • Yes, they're not accidentals. Aug 17, 2021 at 18:12

5 Answers 5


There are a lot of answers pointing out that "passing tones," well, pass between pitches. But I wonder whether you're thinking of "leading tones"? If you found an F# in your C major, the best explanation is that it's "tonicizing" the dominant of G major; that is, even though you didn't change key signatures officially, you're sort of briefly "in" G, maybe only for a few chords. And in that context, it could be reasonable to call the F# a "leading tone."

  • 2
    Nice thought, but doesn't justify Bb etc. (Which won't often be a leading note in any key..!)
    – Tim
    Aug 17, 2021 at 17:34
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    Edit-edit: Duh, the voice-leading meaning of "leading tone" doesn't have to be a non-chordal tone. My bad. But don't let this cloud the waters too much: The biggest takeaway should be "What you call a note depends on context." If you see notes that don't belong in the present key, your job is to explain them, and yes, often they're doing their "usual jobs" for a "temporary key." Aug 17, 2021 at 18:37
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    @Tim No, you are completely wrong! Any note a half step away from another can function as a leading tone. And especially when a tone is flattened or sharped relative to the current key, it can function as a leading tone. You are making the mistake of thinking that because the 7th degree is named the leading tone, that that term is not applicable to anything else. From Wikipedia, if you don't believe me: "In music theory, a leading-tone is a note or pitch which resolves or 'leads' to a note one semitone higher or lower, being a lower and upper leading-tone, respectively."
    – yamex5
    Aug 17, 2021 at 21:46
  • 1
    Keep in mind the new tone is a leading tone only as the keys go up by fifths. Going down by fifths the new tone is a subdominant. And of course none are passing tones. Aug 17, 2021 at 22:31
  • 2
    @user3235 - maybe the subtle difference is between the leading tone and a leading tone. Mine was referencing the leading tone (from a particular key).
    – Tim
    Aug 18, 2021 at 6:15

Passing tone is a concept that is meaningless outside of a harmonic context. Any note can be a passing tone in any key. See the definition at Dolmetsch online:

notes that pass by a tone (step) or semitone (half-step) between chord notes.

Thus, if you have a piece in C, and, during the final cadence, there is a part that plays G-A-B-C-D over the dominant chord before moving to C on the tonic, A and C are passing tones. But if a part has A-B-C-D-E over an Am chord, B and D are passing tones.

You are certainly correct that F♯ and B♭ are (historically, at least) the most likely accidentals to be used in C major, but "passing tone" isn't the term that denotes this phenomenon. In fact, I am not aware of such a term. One often speaks of "borrowing" chords from closely related keys, and it would not be unreasonable to speak of borrowing pitches from related keys, but I haven't encountered that terminology before.

(Furthermore, it seems that calling it "borrowing" implies a stronger distinction between diatonic and non-diatonic pitches than is probably warranted.)


No, not at all. Passing tones don't have to have accidentals.

Quote from https://en.wikipedia.org/wiki/Nonchord_tone#Passing_tone

Passing tone

A passing tone (PT) or passing note is a nonchord tone prepared by a chord tone a step above or below it and resolved by continuing in the same direction stepwise to the next chord tone (which is either part of the same chord or of the next chord in the harmonic progression).

passing tone example 1

Where two nonchord tones are before the resolution they are double passing tones or double passing notes.


Passing tone

A tone that sits between two chord tones and is between them.

passing tone

The example note (F, highlighted in red) is not sharp or flat, no accidentals anywhere, and the definition of "passing tone" doesn't mention sharps or flats or key signatures or keys.

Other examples in the Wikipedia article are similar.


Not necessarily! A passing tone (or passing note) is a non-chord note. Thus it doesn't have to be an accidental - a note which is not diatonic. It could be either, an accidental or a diatonic note which happens not to be a chord tone at that point, but it ain't necessarily so (apologies Gershwin...)


You have this first example...

G, the key of, has an F#. Is that F# also considered a 'passing tone' in C?

But you didn't finish the through for the two sharps example...

the next passing tones would be two keys away (C# the next additional accidental going up two keys

Is that supposed to then read as...

D, the key of, has an F# and a C#, also considered passing tones in C.

...or something like that?

Two things confuse me:

  • passing tones is a very clearly defined concept - non-chord tones between chord tones, which isn't the concept you're presenting
  • Why make the "passing tone" reference to C major? How is that supposed to apply in the given key, G major? Even if you accept this concept, what are you supposed to do with it?

Anyway, I think the easiest way to explain the answer is "no", is by selecting a key with a sharp/flat on the tonic. Ex. Eb major, there is an Eb in the key signature. In what sensible way is the Eb a passing tone when it is the tonic? Other than the standard meaning of passing tone, a non-chord tone between chord tones.


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