After reading Devorah Bennu's post (thanks Devorah!) which included a
brief reference to "plastic song," I did a little web search and came up
with this web page. It does a great job explaining the song phases, and
includes brief illustrative/illustrated audio clips. Enjoy!

http://blb.biosci.ohio-state.edu/stages.htm

Mary

Mary E. Klein
Seattle WA
bassclef at seanet.com