[Harp-L] Numbers Game

[Elizabeth Hess <TrackHarpL@xxxxxxxxxxxx>]

Why are they called 9th chords and 11th chords and not 2nd chords and 
4th chords?  Is the difference between a Maj6 chord and a 13th chord 
that in the 13th chord the 7th, 9th, and 11th are in there, too?  Or is 
the difference the octave in which the note-in-question (6th/13th) is 
played?

A major 6th chord and a minor 7th chord seem to have an awful lot in 
common:  Am7 vs C6, for example.  Is one not an inversion of the other? 
 Is there any value in thinking of these as "enharmonic chords"?  Is 
the decision of what to write on the chord sheet dependent on context?  
Something else?

When can you play a chord in any inversion that's convenient, and when 
is the inversion played (or written) significant?

These are not burning questions...  Just stuff that's rattling around 
in my brain that won't go away.

Thanks in advance.

Elizabeth (aka "Tin Lizzie")