Frank Sinatra was arguably the most famous Italian-American Catholic of the 20th century. The skinny kid from Hoboken, N.J. — who was born 105 years ago, Dec. 12, 1915 — grew up to become synonymous with the so-called Great American Songbook. That songbook, however, was largely written by Jewish-Americans, including immigrants and children of immigrants. And while the songwriters for the most part expressly tried to leave behind the accents and inflections of the Yiddish-speaking world from whence they came, the songs nonetheless often betrayed the influence of Jewish Eastern Europe in outlook and emotional temperament. Sinatra, as it turned out, just happened to become the greatest interpreter of that body of work.