D 13 b5 b9 or Ab 7+9 ?

Hi all,

It makes much more sense to call it a D 13 b5 b9 than the Ab 7+9.

And agree when he says "tritone substitution" is nothing but a shorthand, a tool, not an harmony concept.

I think we're mixing ease-of-reading or ease-of-writing with harmony. When I see this shape:(frets, from bass to treble)
4 6 4 5 7 7

It surely looks like an altered Ab;

When I see on a score Ab 7+9 /maybe/ I would go faster to that shape than if I saw a D 13 b5 b9.


BUT this is not about music, this is about what I really want to do: if I want to play the songs over and over always in the same manner, easily going to that "correct" chord shape, then I might think of that as a Ab chord. If I want to understand what I'm doing and choose the chord shape that better suits what I am trying to tell, depending on the other musicians (maybe that chord is too busy for formations larger than a trio...)

Also, I think inversions are quite common, so if I saw this G7 chord before a C maj:

B D F
3 5 b7

I would not call it a B dim:
B D F
1 b3 b5

although it would be much easier, for someone reading a chart, to play that shape right on the spot.
Inversions have been used for centuries, and allow wonderful possibilities. But thinking of them as another chord is sterile and obscure.

Hope this post was not too obscure as well....:)