The Great American Songbook isn’t really a book. Rather, it’s a notional collection of several hundred pop songs. The precise identity of the songs varies according to who is doing the collecting, but in almost all versions the bulk of them were composed, starting in the 1920s, by a small (almost all male) group of composers and lyricists including George and Ira Gershwin, Cole Porter, Irving Berlin, Richard Rodgers (teaming first with Lorenz Hart and later with Oscar Hammerstein, II), …