Bernstein loved jazz and it pops up everywhere in his music.  According to the New York Performing Arts Library’s Bernstein exhibit, these are some of the songs he listened to on the radio as a child.

“Jazz was everybody’s music. Everybody danced the fox trot and knew how to sing “Alexander’s Ragtime Band” whether he came from Texas, North Dakota or South Carolina.”  (Young People’s Concerts, pg. 40 )

“The thing that makes jazz rhythms so special is something called syncopation, which means getting an accent where you don’t expect it – or getting a strong beat where a weak beat should be.” (Young People’s Concerts, pg. 44)

In an October 1955 telecast about the world of jazz, Bernstein says he loves jazz “for its humor. It “fools around” with notes, so to speak and has fun with them. It is, therefore, entertainment in the truest sense.” He also says he loves when jazz musicians improvise simultaneously. “Neither one knows exactly what the other is going to do; but they listen to each other, and pick up phrases from each other, and sort of talk together.”(The Joy of Music)  

There’s a moment in the Alcibiades, when Bernstein writes out what sounds like an improv between the violin and the solo upright double bass. It could be right out of a jazz club!  (start around 6:20-6:41 in the recording below)

Leonard Bernstein: What is jazz?