Harold arrives, and after he reminds her of the untrue rumors he's heard about her, she convinces herself that Charlie invented everything he told her. They agree to meet at the footbridge, where Marian tells him the difference he's made in her life ("Till There Was You"). Marcellus interrupts and tells Harold that the uniforms have arrived. He urges Harold to take the money and run, but Harold refuses to leave, insisting, "I've come up through the ranks... and I'm not resigning without my commission". He returns to Marian, who tells him that she's known since three days after he arrived that he is a fraud. (Harold earlier claimed to have graduated from the Gary Conservatory in 1905, but Gary, Indiana, was not founded until 1906.) Because she loves him, she gives him the incriminating page out of the Indiana State Educational Journal. She leaves, promising to see him later at the Sociable. With his schemes for the boys' band and Marian proceeding even better than planned, Harold confidently sings "Seventy-Six Trombones". As he overhears Marian singing "Goodnight My Someone", Harold suddenly realizes that he is in love with Marian; he and Marian sing a snatch of each other's songs.