I am currently doing part writing, and have come into a bit of a conundrum. I want to use a sharp 4 dim 7 (Fsharpdim7), to link up my IV chord (FM) to my V7 chord (G7).
I know that 7ths should usually be prepared in the previous chord, or approached by leap if this is not possible. However, when I adhere to these rules in this case (particularly approaching the dim7th by leap), the end product sounds terrible. So, in the pictured example, I have tried to move the voices as little as possible, only moving by step and maintaining all common notes. When I play this as all 7th chords (FM7, Fsharpdim7, G7) it sounds great, but here my first chord is an FM triad, so we move from F (doubled root) to Eflat (dim7th) then to F (7th of G7). It doesn't sound as good, but is this none-the-less the correct/ best way of voicing this progression? Is there anything else I should know about voicing these passing dim7th chords?