Can't help on the Dim chord. BIAB does not distinguish between Xdim and Xdim7. This is a long-standing Wishlist item. Some styles will sound only the triad but most will slip in the diminished 7th (i.e., enharmonic as the 6th). And this differs from a half-diminished chord, such as Xm7b5, in case that is what you were looking for.

To see what chords BIAB can support, right-click on a cell and look at the Chord Builder. There are a few oddities - call them conventions - like the C5b. If that were entered as Cb5, there would be ambiguity as to whether it meant C with a flatted fifth, or Cb = B with the perfect fifth added (power chord).

To see why Dim is interpreted as Dim7, look at the file in the /BB folder called pgshortc.txt


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.