Bb, Ab/ A C Eb Gb as you wrote
this is the related diminished But i do not use this as a chord like it is written by you above Those are available notes that can be superimposed along with the notes of a Bb-7 not even the dominant 7 as you have it written my examples were in Db
even in the key of f it would be a Bb major 7 not a Bb7
Its used in many other ways but I was not advocating that that be used as a chord
Bb F Ab/ Ab B D F
these are the roots of the family of seventh chords you rote them like a chord but I dont play that as a chord
the notes to the right of the slash are the available triads or seventh chords that you can apply over that shel
those are notes not chords they are not written to be played as individual notes they are written to show you the availabvle chords when you see me write something out like you did above that is a chord
I never wrote what you did above
Look at this list again it answers all the questions you asked me
Db uses triads B, D, F, Ab
Eb, uses triads Db E, G, Bb
F uses triads Eb, Gb, A, C,
F# uses triads E, G, Bb Db
Ab uses Triads B, D, F, Ab
Bb uses B, D, F, Ab
C uses A, F#, C, Eb
1. simply go to the dominant of the chord you want to phatten
2. build a diminished on its third degree
3. then lower that diminished chord a half step
thats it three steps and you have your family of sevenths
all the questions that you have aslked me are contained right here if you insist on looking for a shorter way to understand this then you are just causing yourself confusion
sorry you didnt like the chords I guess it is not for everyone
but the notes are correct the
I wrote you a chart you really should read that all the chords are listed