Bridge (music) - Classical Music

Classical Music

In classical music, bridges are common and are known as a specific Sequence form, also known as transitions. Formally referred to as a bridge-passage, they are used to delineate separate sections of an extended work, or to smooth what would otherwise be an abrupt modulation such as the transition between the two themes of a sonata form. In the latter context, this transition between two musical subjects is often referred to as the "transition theme"; indeed, in later Romantic symphonies such as Dvořák's New World Symphony or César Franck's Symphony in D minor, the transition theme becomes almost a third subject in itself.

In a fugue: "A bridge is a short passage at the end of the first entrance of the answer and the beginning of the second entrance of the subject. Its purpose is to modulate back to the tonic key (subject) from the answer (which is in the dominant key). Not all fugues include a bridge."

The latter work also provides several good examples of a short bridge to smooth a modulation. Instead of simply repeating the whole exposition in the original key, as would be done in a symphony of the classical period, Franck repeats the first subject a minor third higher in F minor. A two-bar bridge achieves this transition with his characteristic combination of enharmonic and chromatic modulation. After the repeat of the first subject, another bridge of four bars is needed to lead into the transition theme in F major, the key of the true second subject.

An example of a bridge-passage used to separate two sections of a more loosely organized work occurs in George Gershwin's An American in Paris. 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."