Layman's terms please!

[A440A at aol.com]

<< How would one explain this to a client in layman's terms?
Equal temperament bearings (all figures in Hz)  >>

          Tell them that ET has all notes separated by the 12th root of 2, 
(dividing the octave into 12 parts). Each key signature has identical amounts of 
dissonance.   All major keys have the same harmonic content, as do the minor 
keys,  differing only in their pitch centers. 
     Tell them it is a way to erase all the harmonic differences between the 
keys, and that it is a tuning perfectly suited to the music composed upon it, 
(1900 and later).  Tell them that it is a tuning based on a mathematical 
concept, and arose as a result of factory standardization.  It is like off-the-rack 
clothing, designed to fit as broad a range of users without being optimum for 
any of them. 
Regards, 
 
Ed Foote RPT 
http://www.uk-piano.org/edfoote/index.html
www.uk-piano.org/edfoote/well_tempered_piano.html