MacDonald's singing helped make this film a major hit, coming on the heels of her other 1936 blockbuster, Rose Marie.

On New Year's Eve, 1905, saloon keeper "Blackie" Norton hires Mary Blake to sing in his bar, the Paradise Club on Pacific Street in the notorious Barbary Coast of San Francisco.

Mary is hired by the Tivoli Opera House on Market Street, where she becomes involved with Nob Hill scion Jack Burley.

Backstage on the opening night of her return performance, Father Tim drops in and is angered by Mary's skimpy stage costume.

She rouses the audience to join in a chorus of "San Francisco" and wins, but Blackie refuses the prize money and states that Mary had no right to sing on behalf of his club.

As people shout about building a new San Francisco, Blackie and Mary join the crowd as they leave the park marching arm-in-arm, singing "The Battle Hymn of the Republic".

The original release features a stylish montage of then-current (1936) scenes of a bustling San Francisco, including Market Street and the construction of the Golden Gate Bridge.

[9] Gable and Tracy also made two other films together, Test Pilot and Boom Town, before Tracy eventually insisted on the same top billing clause in his MGM contract that Gable had enjoyed, effectively ending one of the American cinema's most famous screen teams.

[citation needed] Gable had played an extremely similar character also named "Blackie" two years earlier in the smash hit gangster epic Manhattan Melodrama, with William Powell and Myrna Loy.

During the two operatic scenes in the film, MacDonald sang excerpts from Charles Gounod's Faust and Giuseppe Verdi's La Traviata.

[2] Frank Nugent, writing in The New York Times, described San Francisco as "prodigally generous and completely satisfying," its musical sequences "woven gracefully into the script," and its earthquake "a shattering spectacle, one of the truly great cinematic illusions; a monstrous, hideous, thrilling débâcle.