Willow Falls, a small lumber town in the Middle West, is the setting for an imaginary incident in the life of Anton Dvorak, the great Czech composer.  He arrives there in a state of depression seeking inspiration to write a symphony in tribute to America and worthy of what he calls the New World.  By accident his valise has been exchanged for one labelled “Tomashek” and he does not disclose his identity when the inhabitants, reading the label, mistakenly accept him as Tomashek.

The majority of the lumbermen are Czech immigrants, but the land, the trees, the sawmill and the saloon are owned by a domineering widow, “Ma” Flannagan.  With one exception she has bought up every parcel of land so that a rail-road can be built, by which she hopes her son Shaun will become a millionaire.

The other plot of land is owned by Marek.  His attractive daughter Milli is barmaid in Flannagan’s saloon.  She is courting Joe, a pedlar whom she sees only once a year.

Marek’s niece, Karolka, arrives unheralded as an immigrant.  She and Dvorak at once become great friends and both get jobs in the saloon; he as a pianist and she as a barmaid.

Unaware at their first meeting that Shaun is a Flannagan, she smartly rebukes him for trying to be “fresh” with her; but despite all, they soon fall in love.

Dvorak, in his close contact with the pioneers, finds inspiration in a wealth of new sound and folk music to speed his composition.  Abe, a Negro handyman, tells him how he overheard Ma Flannagan planning to trick Marek into parting with his land.  Dvorak, by bluffing his hand ina game of poker with Ma’s agent, wins from him the sum of money that Ma had given him with which to buy Marek’s land.  So Dvorak turns the tables on Ma, and eventually gets from her a splendid price for Marek’s land.

Milli is more fortunate in her love affair than Karolka.  Joe turns up on his annual visit, during which Milli and he get married.

When Ma Flannagan becomes aware of the romance between Shaun and Karolka she sends her packing under threat of expelling her friends and relations from Willow Falls.  Ma has dreams of a brilliant social future for Shaun in keeping with the fortune she is amassing for him.  She had under-estimated his love for Karolka and knows she is defeated with he turns to drink for solace in the belief that Karolka has deserted him.

When the time comes for Ma to take over Marek’s land, he announces that Milli and Karolka are joint owners with him and that it will be necessary to find them before a sale can be made.  A chance remark from Feeney enlightens Shaun that his mother drove Karolka away.  This sobers him and he sets out to find her.

Meanwhile, Dvorak has completed his symphony and returns to New York to conduct its first performance.  It is he who finds Karolka on board ship departing for Europe.  He takes her to the conductor’s room at Carnegie Hall, where the Flannagans, Marek, Milli and Joe are assembled.  There the land deal is settled, and the lovers are reunited.

Then comes the dramatic moment when an attendant announces “The orchestra is waiting, Dr Dvorak”, and those he had befriended gaze in awe at the great man as he takes and baton and goes out to achieve his greatest triumph.