Peter's point about the root reflects what I was saying about the difference between playing and recognising chords with an apc and a non automatic instrument in the other thread.
C79 or C9 = C E G Bb D, CM79 or CM9 = C E G B D, Cm79 or Cm9 = C Eb G Bb D
Back to the beginning, the C D E G A = A7sus4 is because in Fingered mode you are judging four notes, so out of that group the best it can salvage is the D E G A. Switch to pianist and you recognise 4 notes and a bass note.
The thing about pianist mode is that it is effectively automatic on bass... try playing a note more than a fifth from the lowest note of the right hand chord and see what happens...
Since we obviously have Brian Rodwell fans, I remember a good friend who knew him well telling me that he used to play 8 to the bar BASS at 180 bpm with huge chords in each hand. He would play melody in the left hand, 8 in the bar bass, and 16 in the bar right hand chords then as an ending play a chromatic run as fast as most players could play a run with one finger.... but with block chords in both hands alternating chords between each hand....
