La Rocca was the son of poor Italian-American immigrants. 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. La Rocca at first worked as an electrician, playing music on the side.
From around 1910 through 1916 he was a regular member of Papa Jack Laine's bands. While not considered as one of the most virtuosic or creative of the Laine players, he was well regarded for playing a solid lead with a strong lip which allowed him to play long parades without let up or to play several gigs in a row on the same day.
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. This band became the famous Original Dixieland Jass Band, making the first commerically issued jazz recordings in New York City in 1917. These recordings were hits and made the band into celebraties.
Soon other New Orleans musicians began following the O.D.J.B.'s path, arriving in New York to play jazz. La Rocca was uneasy about competition. Frank Christian recalled that La Rocca offered him $200 and a return railway ticket to go back home. After a band featuring New Orleans musicians Alcide Nunez, Tom Brown, and Ragbaby Stevens[?] won a battle of the bands against the O.D.J.B., drummer Ragbaby found his drum heads all mysteriously slashed.
The band gave La Rocca the nickname "Joe Blade", and published a song called "Joe Blade, Sharp as a Tack"
La Rocca led this band on tours of England and the United States into the early 1920s, when he suffered a nervous breakdown, and returned to New Orleans and retired from music, going into the construction and contracting business.
In 1936 he reunited the O.D.J.B. for a sucessful tour and more recordings. La Rocca proclaimed that he and his band were the inventors of the now nationaly popular Swing music. Personality conflicts broke up the band again the following year, and La Rocca again retired from music.
In the 1950s he started writing numerous vehement letters to newspapers, radio, and television shows, stating that he was the true and sole inventor of jazz music, and that those who claimed that the music had Negro origins were part of a Communist conspiracy.
When Tulane University established their Archive of New Orleans Jazz in 1958 La Rocca donated his large collection of papers related to the O.D.J.B. to Tulane, after adding numerous glosses in the margins, often very insulting to his fellow musicians, and occasionally modifying documents to make them more in line with his own version of history.
At the same time, he worked with writer H.O. Brunn on the book The Story of the Original Dixieland Jazz Band (sometimes sarcastically nicknamed by jazz historians as "The Gospel according to Nick La Rocca"). While Brunn toned down some of La Rocca's most extreeme rhetoric, the book still presents a curious tale of La Rocca growing up in a New Orleans apparently devoid of African Americans where he founded the Original Dixieland Jass Band in 1908 (8 years before anyone else recalls it existing). The book is dismissive even of the other members of the O.D.J.B.; it is perhaps kindest to clarinetist Larry Sheilds who was already dead at the time, but still it claims that Sheilds, unlike La Rocca, was not an essential member of the band.
Those trying to assess La Rocca's contributions to jazz are sometimes perhaps as much hindered as helped by La Rocca's own statements. A small few (mostly in England) have taken La Rocca on his word, while a much larger segment of jazz historians have simply dismissed him out of hand. La Rocca may have inadvertantly done much damage to his own reputation, especially in some of his statements which are unusually racist even when compared to interviews with other white southerners born in the late 19th century, and his dismissal if not outright insults of his fellow white musicians.
If few of his contemporaries had anything kind to say about La Rocca, it should be remembered that they were very aware of how he had little kind to say about them. La Rocca's statements in his later life were made when he was not completely well. A balanced assesment may be to regard LaRocca as an important figure in taking jazz from a regional style to international popularity, the leader of the most influential jazz band of the period from 1917 to 1921, a good player in a very early jazz style on records such as "Clarinet Marmalade", and unfortunately his own worst enemy with his bragging in his old age. La Rocca's playing and recordings were an important early influence on such later jazz trumpeters as Red Nichols and Bix Beiderbecke.