John's invitation to consider September as temporal cusp brought up many thoughts of past and present, among them some musical examples that are supremely worth sharing: Kurt Weill's September Song was originally written for Knickerbocker Holiday in 1938. It's been covered by all manner of singers, but surely Lotte Lenya's, Frank Sinatra's, Jimmy Durante's and Sarah Vaughan's versions are standouts, and expose different essences of the text:

and then I discovered Eartha Kitt's version, a marvelous OTHER reading:

Another song redolent of the changes and Changes is from The Fantasticks, and reminds me poignantly of the early 1960s:
"...when you were a tender and callow fellow..."

(it is recommended that you NOT drop acid and watch the Julie Andrews version)