In a choral-style piece I am writing, someone said that this vii° chord (within a phrase) never resolves properly. I would be grateful if anyone could give me some advice about whether it works or not, or how to correct it so that the diminished chord resolves effectively.
The way the
E is doubled you do need to move the voices in contrary motion to avoid parallel octaves to
D. Considering that it seems OK.
Maybe their expectation is to double the tonal degree
G so the outer voices are
E C# to
D D. The doubled
G then moves by contrary motion to the inner voices
F# A. Like this:
When it comes to the question of double degrees in four part harmony, I go by Walter Piston's simple rules: in root position double the root, in chords of the sixth double a tonal degree.
The dim vii is also considered as an incomplete V7 (without root tone), it was used before the the dominant7 chord came up (in 1st inversion like in your example). Doubling the 3rd and also the 5th is practical and I can't see anything wrong in your solution. As there is no tension of the 7th (A-G) there is no need to resolve G to F#.