Twentieth Century Harmony

I'm reading this book "Twentieth Century Harmony" by Vincent Persichetti.
http://www.amazon.com/Twentieth-Century-Harmony-Creative-Aspects-Practice/dp/0393095398/ref=sr_1_1?ie=UTF8&qid=1382546091&sr=8-1&keywords=twentieth+century+harmony

He made an interesting comment on pg. 75 "It is possible to build seven different seventh chords with major and minor construction".
When I first read this, I thought I could finally "Get" all the sevenths down. So I went through the exercise and wrote them all down.

Too bad it was all a waste of time. Paul Hindemith doesn't put strict rules on what constitutes a 7th chord, in fact the only other place I know who does is wiki.
And we all know how useless wiki can be. To be fair, Vincent did not say these were the only 7ths.

In the end, I did not "Get it", and the time I spent finding all those seven 7ths was a waste. There are many more 7ths. i.e. b5 ones.

C E G# B ->Aug Maj 7th
C E G B -> Major 7th
C Eb G B -> min Maj 7th
C E G Bb -> Dom 7th
C Eb G Bb - > min 7th
C Eb Gb Bb -> Half dim
C Eb Gb Bbb -> Full dim

What 7th chord do you like playing that is not on the list above?

For me, it is the French 6th, it has fun working with that chord.

I like sus4 a lot
C F G Bb, it works really well in the IIIrd degree of a major scale (though it is a minor chord in that place) when resolving to the I. It brings some new sound.

Let me explain, instead of playing G7 to Cmaj7, I'll play Esus4(b9 optional) to Cmaj7, it sounds really "fresh" to my ears.

Aside: on the susb9, I use it like this:

Gsusb9 (G C D F Ab) CMaj7
3x311x x3200x

On other 7th chords: C7#5. I guess he's only considering major and minor thirds.

I like sus4 a lot
C F G Bb, it works really well in the IIIrd degree of a major scale (though it is a minor chord in that place) when resolving to the I. It brings some new sound.

Let me explain, instead of playing G7 to Cmaj7, I'll play Esus4(b9 optional) to Cmaj7, it sounds really "fresh" to my ears.

Esusb9 is E A B D F, which could also be a G13, among other things. What sort of grips do you use for Esusb9 CMaj7?

It is a G13 indeed, here's one voicing I use :
XX7767 to a basic Cmaj7 XX5557 it sounds smooth.

Or I use X7710107 to X799107