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I recently came across a piece of music which looked to be in the key of C major or A minor - i.e. there were no flats or sharps in the key signature. However, it's actually in G major - it just happens not to have any Fs (either sharp or natural) in it.

I understand the rationale for it in this case (it is beginner music for a leverless harp tuned to C major), but I was wondering if this would generally be considered to be wrong. I'm reasonably sure it is, but it's not something I've come across before and would be interested in a good explanation of why it's wrong (assuming it is).

marked as duplicate by guidot, Dom theory Jun 29 '18 at 17:39

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Technically it is incorrect. But for a beginner that doesn't know what a key signature or possibly even an accidental is it makes sense to leave it out. Putting the key signature in could possibly confuse someone, but if I was writing music even for beginners I would put it in.

A good teacher should point this out. It gives a great opportunity for a little ear training lesson and can be a good introduction to why we have different keys, what a key is, what a tonic is, why we hear a resolution when we do, and possibly many other topics.

My daughter just got to the point where she is learning about sharps and flats and is playing a piece in G and all the sharps are written in without a key signature. Again this is probably not correct but for a beginner it makes sense.


One consideration - not having any F#, and for a beginner = less complicated.

Second consideration, if G sounds like home, (and especially if Fnats are there) it could be construed as being in G Mixolydian. G Mix. uses all the notes from the Cmaj. key/scale, including Fnat., but roots on G. Because there will be no # of b, the key sig. looks like C - blank! It gives a sort of bluesy feel to the piece - and harps are good for that.

Yes, it is considered wrong, technically. The first thing most sightreaders would look for is the key sig. It usually (but not here) allows them to choose which 'hat' they wear to play the piece. It usually gives clues as to harmony, chords, home, etc.

  • There are no F naturals either, and I'm reasonably sure that it's simply in G major (the piece is "Loch Lomond"), but interesting answers like this are part of the reason I asked the question :) – Guy G Jun 29 '18 at 9:28
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    If there were no C notes either, it'd be in G pent. maj. – Tim Jun 29 '18 at 10:19
  • “Harps are good for bluesy feel” – pun intended? – leftaroundabout Jun 29 '18 at 15:40
  • @leftaroundabout - what pun? Most of the guys I play with who play harp (mouth-organ/harmonica) use them for blues. – Tim Jun 29 '18 at 16:02
  • @GuyG Loch Lomond is definitely in a major key. – Cullub Jun 29 '18 at 16:19

I call it wrong. "dumbing down" is never a good thing. In this case, it's more likely to confuse a "beginner" into thinking it is in C, and then how the heck does it resolve, perhaps, on a G-B-D chord? Makes about as much sense as writing a piece in g-minor that has no Eb or Bb in it and leaving the key sig blank.

  • You could equally argue that it's 'dumbing down' to pretend it's in a key at all. Key signatures are for keys, not to indicate the root note of a mode. – Laurence Payne Jun 29 '18 at 15:50
  • @LaurencePayne that makes exactly no sense at all. – Carl Witthoft Jun 29 '18 at 17:41
  • That g-minor piece could have an F# in the key sig. That would really mess things up... – Tim Jun 29 '18 at 21:15
  • @Tim That d-minor piece could have a B♭ and a C♯ in the key sig. That would really mess things up. – user45266 Nov 30 '18 at 17:43
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    @user45266 - Someone - Bartok, maybe - did try using key sigs such as this. Never really caught on. I think I can guess why! – Tim Nov 30 '18 at 19:57

On most instruments, a key signature merely indicates how notes on the staff should be interpreted when they are encountered. On some others, however, a key signature may indicate how an instrument should be set up. Indeed, on some of the latter instruments, switching between an altered and unaltered pitch may take long enough that playing accidentals would be essentially impossible unless they are set up before the performance begins.

When writing for instruments of the former kind, there is a very strong convention that pieces which are in Lydian and Mixolydian modes use the same key signature as the corresponding major key (Ionian mode) and add accidentals, and likewise that those in Dorian or Phrygian modes use the same key signature as the corresponding minor key (Aeolian mode), also adding accidentals. If a piece like "The Little Drummer Boy" (Mixolydian mode) is rooted on G, it would have F naturals but not F sharps. Nonetheless, most performers would find it easier to read with an F sharp in the key signature and natural accidentals before each F, than it would be without the sharp in the key signature and accidentals on the notes.

When writing for instruments of the latter kind, however, what is most important is ensuring that the performer correctly sets up the instrument before the performance begins. If a performer will have to change to switch a string between F sharp and F natural during a performance, including an F sharp in the key signature and F naturals throughout the score would be disastrous if it caused the performer to configure the instrument to play F sharps. Even if the performer configured the F strings to play naturals, littering the score with F natural accidentals would serve no purpose since the performer who encounters F's in the score would have no chance to play F sharps whether or not the notes were marked.

If a piece has no F notes at all, then it would make sense to play with the instrument configured for C major if the preceding and following pieces are also in that key, or for G major if the preceding or following pieces are in that key. If editor would expect the piece to be performed between two other pieces that are in C major, adding F sharps to the key signature would require at minimum adding a note at the start of the "G major" piece indicating that there is no need to change the instrument's tuning. While that might be workable, it may be easier to simply omit the key change.


'Loch Lomond', like much folk music, uses a pentatonic scale. (The quick test for a pentatonic tune is whether you can play it using just the black notes on a piano - though that would of course be transposing it into Gb pentatonic.) So, although it homes on G, it isn't technically 'in G major'.

I suspect quite a lot of music intended for 'folk harp' tuned to the C scale may be in G pentatonic rather than C major.

Most printed copies of 'Loch Lomond' use the key signature of the major key. But then, most collections of folk music were prepared 50 or 100 years ago, when we didn't really fuss with stuff like modes. Using an F# key signature may be 'wrong', but it's common and fairly harmless.

  • I think in that last sentence you mean "using a key signature with F# in it" or did you mean "using a G key signature"? – b3ko Jun 29 '18 at 13:35
  • Just to clarify, are you saying that the natural key signature is correct, because it's in G pentatonic, rather than G major? And presumably a D pentatonic piece would require a key signature with a single sharp (F)? – Guy G Jun 29 '18 at 13:47
  • Well, I wasn't going to suggest a key signature of 6 sharps, was I? :-) We're not in 'keys' any more. What's 'correct' is very much a matter of debate. We could consider a one-sharp signature and no signature equally useful. – Laurence Payne Jun 29 '18 at 14:36
  • Looking at it now, I don't think it's on a pentatonic scale - every natural note apart from F appears at least twice in it. It seems more like G major. – Guy G Jun 29 '18 at 17:40
  • The word 'never' in 'never meet again' is on a C. Not pentatonic. – user207421 Jun 29 '18 at 17:58

With no F# how do you come to the conclusion that it's in G? Does the melody (or melodic phrases) begin and end on notes from the G major chord? Are there occurrences of a D power chord (no F#) going to G that tries to define a cadence? Or is it a major pentatonic melody in G that meanders about?

I know I'm asking more questions than answering but to give you an answer you need to feed more data. I'd say that if the melody was based on G pentatonic and clearly uses G chord tones as highlights in the melody then the song is in G maj and the composer or arranger is unaware of that. Because they don't explicitly use F# why bother putting it in the key signature. That may seen reasonable but would be a bit confusing to someone sight reading it. However if the song seems to resolve to C then it really is in C. As a counter example, if you wrote a song in C but never used the note B, how would you know it wasn't in F maj? By the abundance of C chord tones, lack of F chord tones (other than the C), and more importantly the structure of the phrases.

  • Yes, I'm basing it on the fact that the melodic phrases end on G, and start on notes from G major. I'm pretty sure there are occurrences of D power chord going to G as well (although the left hand part is pretty simple) – Guy G Jun 29 '18 at 13:45
  • Then I think your analysis is correct. The other question is, are there any F naturals in the song. – ggcg Jun 29 '18 at 14:18
  • No, there are no Fs at all (edited to clarify this) – Guy G Jun 29 '18 at 14:22
  • Got it. It seems like it's in G to me, based on the evidence. – ggcg Jun 29 '18 at 14:27
  • You can consider G pentatonic as being a subset of G major. One sharp is perhaps the most useful key signature. But key signatures belong to keys. We're moving out of that domain. – Laurence Payne Jun 29 '18 at 14:32

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