A quote from the 2009 book, “A Fine Romance,” by David Lehman, subtitled: “Jewish Songwriters, American Songs”:

The lyricists of American popular songs “followed a Jewish imperative in their abundant humor, wit, and cleverness and in their ability to mix sadness with elation and to produce thereby the mysterious tangle of romance. I’m prepared even to argue that the great American standards—such as ‘Blue Skies,’ ‘The Lady is a Tramp,’ ‘I Got Rhythm,’ ‘The Way You Look Tonight,’ ‘My Funny Valentine,’ ‘Tea for Two,’ ‘Love Me or Leave Me,’ ‘All the Things You Are,’ ‘Over the Rainbow,’ and ‘I’ve Got You Under My Skin’—are in some fundamental way inflected with Judaism even when the composer or lyricist was neither by birth nor by conviction Jewish. (Only one of the ten songs I just mentioned was entirely the work of a non-Jew, and he acknowledged that he was ‘writing Jewish.’)”
 
  The song: “I’ve Got You Under My Skin.” The composer: Cole Porter.

  The “romance” in the songs was supposedly the Jewish songwriters’ “passionate romance with America.”
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Lenny Bruce is quoted in the book as saying:

“To me, if you live in New York or any other big city, you are Jewish. It doesn’t matter even if you’re Catholic; if you live in New York, you’re Jewish.”