"[2] The term is a calque from a German word for bridge, Steg, used by the Meistersingers of the 15th to the 18th century to describe a transitional section in medieval bar form.
[3] The German term became widely known in 1920s Germany through musicologist Alfred Lorenz[4] and his exhaustive studies of Richard Wagner's adaptations of bar form in his popular 19th-century neo-medieval operas.
Formally called a bridge-passage, they delineate separate sections of an extended work, or smooth what would otherwise be an abrupt modulation, such as the transition between the two themes of a sonata form.
As Deems Taylor described it in the program notes for the first performance: Having safely eluded the taxis ... the American's itinerary becomes somewhat obscured.
However, since what immediately ensues is technically known as a bridge-passage, one is reasonably justified in assuming that the Gershwin pen ... has perpetrated a musical pun and that ... our American has crossed the Seine, and is somewhere on the Left Bank.