Hi Pierre. The reason your alternate of Ebdim/C works is the nature of the diminished chord's repeating notes, so it's just a question of inversions.

Let's take C as a root.

Cdim = C, Eb, Gb

add the seventh and you get A (Bbb).

If you keep going up for different inversions, you get again to C, Eb, Gb, A etc.

So, you can start a diminished seventh chord on any of its notes as the root, and you have the same notes in the chord, just a different inversion.

Since BIAB plays a diminished seventh anyway, what you have with Ebdim/C is the same chord sound as Cdim just with another C at the top of the chord.


BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Presonus 192 & Faderport 8, Royer 121, Slate VSX, Adam Sub8 & Neumann 120 monitors.