How did music change during the Harlem Renaissance?

To understand how music changed during the Harlem Renaissance, you also need to understand how the Great Migration impacted the culture of the North.  Around the turn of the 20th century, a huge population of blacks started migrating from the South to the North in search of jobs, education, and other opportunities not found in the South.  The South was still a place of oppression and racism with its Jim Crow laws and incidents of lynching.  Blacks were looking for a safer place to live, and one where they could get ahead financially.  The larger industrial cities in the North received the most migrants and include, Chicago, Detroit, Pittsburg, and of course, New York City. 

With them, migrants brought the Blues and instruments of the South.  Primarily acoustical instruments like guitars, banjos, and homemade instruments, they were packed and brought along with their clothing and material possessions.  Blues was the predominant style of music in the South while the North was revving up with Ragtime music like that of Scott Joplin.  Because the North had electricity everywhere, the electric guitar was invented, and the two different music genres combined to form a new one, jazz. 

The meeting of the urban Northern black culture with the rural Southern black culture caused a beautiful melding of the styles, themes, and experiences into a new, unique black experience.   Born from two styles of music, jazz became overwhelmingly popular across all cultures in the United States.