Double Sharps

[tangoloco]

I’m playing a piano arrangement in B Major which frequently uses this chord: B# dim7. The chord is spelled like this: B# D(#) F(#) An. I don’t understand why the spelling shouldn’t be with a G##. For example, another commonly used chord in this arrangement is B+. This chord is spelled as B D(#) F##. Note: Since I can’t find the proper symbols to display here, I am using the following substitutions: () to show chords which are implied by the key signature. n for natural. ## for double sharps.

[jancivil]

any tertial harmony on any B is going to contain a B, a D, an F and to the extent of a seventh, an A {of some description} and so on.
In B major, you're spelling a viiº7 of ii there. The root of a harmony named B# is B#, period.
Gx B# D# F# is the same four notes on a piano but you'll be spelling a viiº7 of vii. A diminished seventh chord seems rootless or to mean any of the four is its root so the distinction made is pure function of the harmony.
B augmented is correctly spelled B D# Fx. Again: any triadic construction is spelled by thirds. Any B triad is a B, a D, an F.

[kvraudio38]

In B the septima has to be an A and if you raise the B to B# the septima still has to be an A of some sort and in B#dim7 it perfectly fits in with a regular A and not Ab or A#. Take a look at diatonic scales theory.

Edit: Jancivil beat me to it and gave you an even more thorough explaination.

[jancivil]

Diatonic scales "theory" cannot explain it; the root of the chord B# is not in B major diatonically, nor is the A natural. If the chord is spelled Gx B# D# F#, Gx is also not in the diatonic set. This is chromatic harmony, full stop. Both spellings of the diminished seventh harmony are secondary dominants. There is no dim 7 diatonically occurring in major; vii7 of B major is A# C# E G#, a half-diminished (diminished triad/minor 7th) chord.

[kvraudio38]

Interesting! What do you mean by "Both spellings of the diminished seventh harmony are secondary dominants"? I know what a secondary dominant (dominant's dominant) is but can't really grasp to what they are this to. Thanks in advance.

[jancivil]

There, the harmony from B# is vii of ii. vii serves pretty much a dominant function (ie., same function there as the full dominant of C#m, G# B# D# F# [A]) to ii, C#m.). Same function, lacks the strong rising 4th root movement but functions as such.

Gx is vii of A#, compare E# Gx B# D# [F#] or V of vii in B.

[tangoloco]

any tertial harmony on any B is going to contain a B, a D, an F and to the extent of a seventh, an A {of some description} and so on.
In B major, you're spelling a viiº7 of ii there. The root of a harmony named B# is B#, period.
Gx B# D# F# is the same four notes on a piano but you'll be spelling a viiº7 of vii. A diminished seventh chord seems rootless or to mean any of the four is its root so the distinction made is pure function of the harmony.
B augmented is correctly spelled B D# Fx. Again: any triadic construction is spelled by thirds. Any B triad is a B, a D, an F.

So An is correct after all. Thanks.

[Romy Schmidt]

I’m playing a piano arrangement in B Major which frequently uses this chord: B# dim7. The chord is spelled like this: B# D(#) F(#) An.

You should post that part of the score. Just because the arrangement is in B major, doesn't mean it's in B major all the way.

[jancivil]

Which has no effect on spelling a seventh chord whatsoever. Here I did give examples of why you would call a B#º7 vs a G#º7 vis the given key, but that aspect of diminished sevenths may be explained via its leading tone to the scale degree in any case. The scale degree's place in the key has naught to do with spelling a tertial construction by thirds.
B# D# F# A is the one way to spell a B#º7 regardless of function or key, as a simple matter.

[Romy Schmidt]

Which has no effect on spelling a seventh chord whatsoever. Here I did give examples of why you would call a B#º7 vs a G#º7 vis the given key, but that aspect of diminished sevenths may be explained via its leading tone to the scale degree in any case. The scale degree's place in the key has naught to do with spelling a tertial construction by thirds.
B# D# F# A is the one way to spell a B#º7 regardless of function or key, as a simple matter.

A diminished 7th chord can have 22 meanings, so 22 different spellings.

[tangoloco]

any tertial harmony on any B is going to contain a B, a D, an F and to the extent of a seventh, an A {of some description} and so on.
In B major, you're spelling a viiº7 of ii there. The root of a harmony named B# is B#, period.
Gx B# D# F# is the same four notes on a piano but you'll be spelling a viiº7 of vii. A diminished seventh chord seems rootless or to mean any of the four is its root so the distinction made is pure function of the harmony.
B augmented is correctly spelled B D# Fx. Again: any triadic construction is spelled by thirds. Any B triad is a B, a D, an F.

So in this song if the harmony is F major and I wanted to write an F major chord I will spell it as: Ex, An, Cn?

[jancivil]

Which has no effect on spelling a seventh chord whatsoever. Here I did give examples of why you would call a B#º7 vs a G#º7 vis the given key, but that aspect of diminished sevenths may be explained via its leading tone to the scale degree in any case. The scale degree's place in the key has naught to do with spelling a tertial construction by thirds.
B# D# F# A is the one way to spell a B#º7 regardless of function or key, as a simple matter.

A diminished 7th chord can have 22 meanings, so 22 different spellings.

The point is the spelling difference - "meaning" - belongs to function. Telling me this after I explained it seems to want to gainsay while saying nothing at all, and is non sequitur. You're trying to move the goalpost but wherever you want it the point remains. I showed the main reason you'd say "B#º7" rather than three other spellings, but as a thing in itself there is one spelling anyway.

Hey, why not go into this "22 meanings"?

[jancivil]

any tertial harmony on any B is going to contain a B, a D, an F and to the extent of a seventh, an A {of some description} and so on.
In B major, you're spelling a viiº7 of ii there. The root of a harmony named B# is B#, period.
Gx B# D# F# is the same four notes on a piano but you'll be spelling a viiº7 of vii. A diminished seventh chord seems rootless or to mean any of the four is its root so the distinction made is pure function of the harmony.
B augmented is correctly spelled B D# Fx. Again: any triadic construction is spelled by thirds. Any B triad is a B, a D, an F.

So in this song if the harmony is F major and I wanted to write an F major chord I will spell it as: Ex, An, Cn?

You seem to not understand one thing I've said, or you're just f**king with me. I can't believe I just read this.
The principle here doesn't lead to that at all.
Clearly an F major chord, as are all tertial harmonies, is spelled by thirds. E to A is a fourth.
Obviously an F chord is identified from the root F. "if the harmony is F major" is redundant to "F major chord".
F major chord is F, A, C regardless of any consideration.

Ex is a leading tone or ^7 degree to F#. It will be the major third to a C# major chord. It will be the minor third to a Cxm, which is probably of no real use because one will call it something more basic, F in a Dm chord. Likened to the original problem, you can make a dimº7 on vii of F#, same as the function of C#7, V7. In B it would do that for its V, secondary dominant. In E it would a tertiary dominant, dominant of the dominant of the dominant; V or vii of V of V. So the further south we go in the flat direction the further away from tonal function of a harmony spelled this way. In F, the meaning of Ex is such a stretch no one is going to do it.

Any way you cut it, it functions in a highly sharp key or area, so its function outside of 6 or 7 sharp keys is obviously highly chromatic, in any case. If there is no function calling for it "E double sharp" has no meaning. Per F it's a member of a key 7 sharps away, the most distant tonality possible. Or it's a member of a key 8 sharps away, by its relative location [C# is] one position in the cycle of fifths closer [than F#]. Outside of that, chromatic function eg., secondary dominants etc.

[jancivil]

"its function outside of 6 or 7 sharp keys" is not the clearest sentence in the world. <Outside of keys with 6 or 7 sharps>


"A diminished 7th chord can have 22 meanings, so 22 different spellings."

bless your heart


Really basic logic: Four note chord has four spellings. Regardless of "meaning". Beginning with "Bº7": B D F Ab; D F Ab Cb; F Ab Cb Ebb; Ab Cb Ebb Gbb. It has to be spelled by thirds, FFS. We're done, there is no more.

By its nature (tensions) its meanings are pretty limited. EG: Schoenberg liked to say it's really kind of a V7b9.
So: G7b9 or Bº7? Same function. If a Dº7 chord it relates to a flatter key area (cf., Bb7b9) than C is, etc.

[tangoloco]

any tertial harmony on any B is going to contain a B, a D, an F and to the extent of a seventh, an A {of some description} and so on.
In B major, you're spelling a viiº7 of ii there. The root of a harmony named B# is B#, period.
Gx B# D# F# is the same four notes on a piano but you'll be spelling a viiº7 of vii. A diminished seventh chord seems rootless or to mean any of the four is its root so the distinction made is pure function of the harmony.
B augmented is correctly spelled B D# Fx. Again: any triadic construction is spelled by thirds. Any B triad is a B, a D, an F.

So in this song if the harmony is F major and I wanted to write an F major chord I will spell it as: Ex, An, Cn?

You seem to not understand one thing I've said, or you're just f**king with me. I can't believe I just read this.
The principle here doesn't lead to that at all.
Clearly an F major chord, as are all tertial harmonies, is spelled by thirds. E to A is a fourth.
Obviously an F chord is identified from the root F. "if the harmony is F major" is redundant to "F major chord".
F major chord is F, A, C regardless of any consideration.

Ex is a leading tone or ^7 degree to F#. It will be the major third to a C# major chord. It will be the minor third to a Cxm, which is probably of no real use because one will call it something more basic, F in a Dm chord. Likened to the original problem, you can make a dimº7 on vii of F#, same as the function of C#7, V7. In B it would do that for its V, secondary dominant. In E it would a tertiary dominant, dominant of the dominant of the dominant; V or vii of V of V. So the further south we go in the flat direction the further away from tonal function of a harmony spelled this way. In F, the meaning of Ex is such a stretch no one is going to do it.

Any way you cut it, it functions in a highly sharp key or area, so its function outside of 6 or 7 sharp keys is obviously highly chromatic, in any case. If there is no function calling for it "E double sharp" has no meaning. Per F it's a member of a key 7 sharps away, the most distant tonality possible. Or it's a member of a key 8 sharps away, by its relative location [C# is] one position in the cycle of fifths closer [than F#]. Outside of that, chromatic function eg., secondary dominants etc.

Thanks. I appreciate your explanation. However, I do not appreciate your sarcasm. I hope if I post here again, I'll be able to receive a response that has more basic courtesy.