SCA.4
                    weak pilot   suppressed    just a
                     carrier      carrier     boundary              FM
                       /            /             /             sideband
                      /            /             /          sub    /
                     /            /             /           car.  /
|             |             |             |            |   /
| Normal FM   | (A-B) Lower | (A-B) Upper |        /||||||||\
| audio (A+B) |  Sideband   |  Sideband   |     /||||S|C|A|||||\
|             |             |             |  /|||||S|i|g|n|a|l|||||\
DC           19KHz        38KHz         53KHz        67KHz
--monaural
    signal----
--------stereo composite signal-----------
-------------full composite (stereo + SCA) signal-------------------



Now to the main point.  The FM transmitter takes this composite audio
signal as input and FM MODULATES its carrier with it.  When this is
received by an FM receiver, what comes out of the discriminator is the
composite signal.  In a normal monaural FM receiver, this is fed to the
volume control and thence to the audio amplifier stages, where
"de-emphasis" is applied as noted above, and finally out to the speakers
or headphones.
CONTINUED IN SCA.5