the statement which says " that #IVd7 is an altered version of chord iv, and as such it is viid7 of the dominant and usually resolves on to that chord".

Where does the resolution go to?

I don't really understand your sentence (are there some words missing?), but I think the statement is saying that chord viid7 (shouldn't that be vii7d?) resolves to the dominant. Would that make sense?

Oh - does the 'd' stand for diminished? I thought it was referring to an inversion.

If I have understood you correctly, chord IV would be FAC in C major, sharpened and with a d7 added, would be Fsharp, A, C, E flat which resolves to the dominant chord GBD. The Fsharp, A C Eflat chord is viid7 of G. Does that make sense?

According to p.84 of the book "Harmony in Practice"



in c minor, iv7 is F Ab C Eb, whereas #ivd7 is F# A natural C Eb

It resolves onto the dominant - in this case, G major (G is the dominant of C) - does that answer your question?

Edit : Oops posted just as you did, let me have another look...

iv7 has F as root, with Ab C Eb as 3rd, 5th and 7th notes above

the sharpened root ivd7 has A natural because a diminished 7th chord is built from minor 3rds. The F sharp and A resolve to D, C resolves to B, Eb resolves to D = G major triad.

Edit again - the viid7 chord of G would be Fsharp, A, C Eb

In the key of C major or C minor, the chord F#-A-C-Eb is a secondary diminished seventh chord, which is also known as applied diminished seventh chord. Specifically, it is the diminished seventh chord of G, which is V of C.

While one can certainly regard this chord as an altered IV7 and thus label it as #ivo7, it is much better to use label it as viio7/V, which shows clearly to which chord this diminished seventh chord should resolve.

You should understand that when a diminished seventh chord is used functionally, its root is in fact the leading note.

... or it can very nicely resolve onto a cadential 6/4 5/3, instead of going straight to a G major chord

I didn't mention the cadential 6/4 because it is a harmonic embellishment to the V chord.

I don't understand if 'd' is the inversion or if its diminished.

Diminished - the d would be at the end for an inversion

Ok thanks it makes sence now!
I'd have written o.

The diminished 5th is implied in a diminished 7th chord (see H in P p79).

maybe as the d comes first?
if it was the inversion then you would write it #iv7d.

It took me several goes through the book to understand and absorb it all . I wrote pages and pages of notes too... Definitely worth it in the end, though.

But then this diminished seventh chord rarely appears in third inversion. It would have to resolve to the second inversion of the dominant triad (extremely unlikely) or the second inversion of the dominant seventh chord (plausible but uncommon).

I don't think it is diminished.
as theres no o it cant be both diminished and third inversion, can it?

The chord under discussion is on p84 of Harmony in Practice : F sharp, A natural, C, E flat - a root position diminished chord based on an altered IVth note.

what is an o?

so Its not an inversion?
you just resolve into a G major or minor chord.

Yes that's right - the d refers to diminished 7th - it is clearer if you see it in the book where the d7 is written in smaller type as a superscript.

I was getting thoroughly confused too, so I went and had a look in H in P. From what I can make out you use the little (superscript) "o" for a diminished triad (3 notes built up on minor 3rds with the bottom and top notes a diminished 5th), and use the (superscript) "d7" for a diminished 7th chord (4 notes built up on minor thirds with the 7th and the 5th being diminished intervals)

so to show its an inversion you need to write #ivd7d?

why not just have an o and keep things simple?

o is for diminished 5th
d7 for diminished (5th and) 7th
d after the chord name for a 3rd inversion

What could posibly be confusing about that?!

Now step away from the theory book.....!

I don't understand why AB don't make the authors of its theory textbooks adopt notation that is used elsewhere in the English-speaking world.

For example, it'd be so much clearer to label inversions of triads with numbers 6 and 6/4, and for the seventh chords, 7, 6/5, 4/3 and 4/2.

I think b,c and d are fine for the inversions and o for diminished.

there is no need for another d for diminished 5ths and 7ths.