Young Nick was attracted to the music of the brass bands in New Orleans and covertly taught himself to play cornet against the wishes of his father who hoped his son would go into a more prestigious profession.

In 1916 he was chosen as a last-minute replacement for Frank Christian in Johnny Stein's band to play a job up in Chicago, Illinois.

LaRocca led this band on tours of England and the United States into the early 1920s, when he suffered a nervous breakdown.

Levine later led one of the house bands on NBC's radio series The Chamber Music Society of Lower Basin Street.

He and the reunited Original Dixieland Jazz Band performed "Tiger Rag" in The March of Time newsreel segment titled "Birth of Swing," released to U.S. theaters February 19, 1937.

In the 1950s, he wrote numerous vehement letters to newspapers, radio, and television shows, stating that he was the true and sole inventor of jazz music, damaging his credibility and provoking a backlash against him and his reputation and career.

[7] LaRocca's playing and recordings were an important early influence on such later jazz trumpeters as Red Nichols, Bix Beiderbecke and Phil Napoleon.

In 2006, his 1917 recording of "Darktown Strutters' Ball" with the Original Dixieland Jass Band was inducted into the Grammy Hall of Fame.