She was known as the comedian's comedian, and one of the few capable of
making Jack Benny laugh at the drop of a hat. Anyway, Edward G.
Robinson was hosting a private party for Grace Moore about the time her
movie (One Night of Love) was coming out in 1934. At some point during
the party, Grace was asked to sing the title song from the movie for
the guests, to which she obliged. As the guests set up a couple of rows
of chairs to listen to her sing, George Burns leaned forward and told
Jack Benny that "it would be very rude of him to laugh when she
starting singing". Of course the minute Grace started to sing, Benny
began to laugh... and continued to laugh. George's punch line... "See,
I don't make Jack Benny laugh... Grace Moore makes Jack Benny laugh".