Summertime (from Porgy and Bess Opera (http://en.wikipedia.org/wiki/Porgy_and_Bess), 1935, music by George Gershwin, libretto by DuBose Heyward, and lyrics by Ira Gershwin and DuBose Heyward), performed by Ella Fitzgerald (http://www.ellafitzgerald.com/) and Louis Armstrong (http://en.wikipedia.org/wiki/Louis_Armstrong) (edition by Dailymotion, http://www.dailymotion.com/pt)