If you want to sing accurately in English, Mitchell Brunings’ story will be useful. You might have heard of him; the man whose version of Redemption Song in the blind auditions of The Voice of Holland sounded like Bob Marley reincarnated:
Summertime: where the music asks the words to stretch out like lazy cats. Ella Fitzgerald makes it all seem extremely easy. So why does the pianist turn round in appreciative surprise (1.43) when Ella sings the word mornings?