Once again, "Rise Up Singing" didn't get it quite right (now there's a surprise). According to Joe Offer's later post on the "Summertime" thread (thread id=4175), the lyrics and the writers differ somewhat:
SUMMERTIME (Words and music by George Gershwin, DuBose & Dorothy Heyward, and Ira Gershwin)
Summertime and the livin' is easy Fish are jumpin' and the cotton is high Oh your Daddy's rich and your ma is good lookin' So hush little baby, don't you cry
One of these mornings You're goin' to rise up singing Then you'll spread your wings And you'll take the sky But till that morning There's a nothin' can harm you With daddy and mammy standin' by