[TPIN] Good or bad,..here it is

[Keith Reynolds]

> 
> The 11th (4th) scale note ever a vanilla major7 chord is *generally*
> considered an "avoid note" unless it's used as a passing tone.  (It
> forms a tritone with the major 7 in the chord.)
> 
> Cb (B natural) in a Fmaj7 would be a #11 if it were a chord tone.
> It's not entirely uncommon but more likely in Chet's case to be a
> chromatic upper/lower neighbor to C that he's laying on to add
> tension.  (I say this without hearing the recording or seeing the
> transcription, so caveat emptor.)
> 
Which is why, of course, some prefer to use the lydian mode/scale for 
maj7 chords.
Keith Reynolds