The new music teacher is Mr. Revelli and he barely looks old enough to be out of high school himself.

But here is he, 23 years old in 1925, huddled in the chemistry lab of Indiana’s tiny Hobart High School, with a handful of anxious students who say they want to be in a band.

None of them has ever touched a musical instrument.

He himself has never played in a band; concert bands don’t use violinists.

The school superintendent made it clear to his new hire: There is no budget, no rehearsal space, no equipment. And there certainly isn’t time during the school day for band class.

* * *

Concert and marching bands—staples of today’s K-12 system and colleges—were an American phenomenon of the 1920s. In the wake of the Great War, the public embraced patriotism and pomp, along with music performed live at silent movies and spread by the phonograph. A growing middle class preferred band music rather than fussier orchestras. The advent of talking pictures brought unemployment to orchestra pits, driving professional musicians to Hollywood, radio—and teaching.

The school band movement was under way.

At Hobart High School, Revelli’s official duties called for him to teach vocal music—all grades, kindergarten through 12th grade—as well as conduct several school choirs and a glee club. Within his first month on the job, he received permission to develop a band program.

The students honked and squeaked and generally crashed through the music. There were not enough players to form a full concert band; they performed minus flutes, oboes, timpani and several other standard instruments. He called it “mess production.”

Still, Hobart parents were keen to hear their young prodigies.

“I had mothers calling and asking me when their child was going to bring his or her instrument home. I used to say, ‘You know, Mrs. Maybaum, you don’t know how lucky you are. I have to listen to him, you don’t. You should be thankful.’”

He was an advocate of solfeggio—the practice of singing the printed notes (“do,” re,” “mi”). Hobart students would hear the same refrain issued over and over to Michigan students 10, 20 and 30 years later: “If you can’t sing it, you can’t play it.”

He also realized his own need to evolve musically, and learned to play trombone, flute, bassoon, trumpet, and more from members of the Chicago Symphony. He took a similar tack with students, teaching them several instruments so they could appreciate an entire body of work. He also arranged for private lessons between his students and professionals, just as his father did when he was 7 years old.

He demanded, and expected, excellence. During one frustrating band practice, he threw down his baton and told the students to get out, just go home. He wouldn’t conduct them if they were the last band on earth. He stormed out of the room.

Stunned, the students did not move. No one said a word. Ten minutes passed before Revelli returned, picked up his baton, and resumed the rehearsal.

He could not deny how much they energized him. He loved watching them express themselves through music.

“They made my day. Anytime I was down, all I had to do was give a lesson, and those kids pulled me right out of it.”

In return, they played their hearts out, for their teacher and their town. The growing school band movement led to state and national competitions, and Hobart High School matured into the best, period.

Said one judge: “The conductor evidently seeks clarity, thoroughness, and musical performance of every tone more than general impressionistic effect. Either as a conscious technique or because of full participation in the mood, these players bring a wider range of color out of their respective instruments than is ordinarily heard.”

When Hobart won its first national championship, in 1930, one of the judges was the great man himself, John Philip Sousa. Revelli all but ran to accept the award.

For five straight years, the Hobart band reigned as finest in the country.

With each national title, Revelli’s reputation grew; professional symphonies, colleges and bigger high schools pursued him. Michigan State came calling, but he felt the school was too small. Wisconsin had him all but moved to Madison, but he changed his mind. “I wanted to make one move and I wanted it to be the right one.”

That right one was Michigan.

In his final Hobart concert, Revelli led students he had groomed since fourth grade. They were his instrument. Closing with “Auld Lang Syne,” tears fell down their faces. One after another, kids couldn’t play through their crying. Mr. Revelli himself blinked back tears.