The correct answer to this open question is the following.
First, we have to clarify something. This is not the correct statement for the question.
The correct question should be read like this: "Explain the significance of Alan Freed renaming race music as rock-and-roll music."
Now, we can comment on the following.
Alan Freed was a famous disk jockey in the 1950s, The significance of Alan Freed renaming race music as rock-and-roll music was that this change allowed him to promote this modern music in different publics, including the white youngsters that immediately fell in love to rock and roll.
What he successfully did was to take the black musicians that played rock and roll like Little Richard and Chuck Berry, to the massive white audience that had the money to buy records and buy tickets. And sell records and tickets he did, because he promoted r&r music and produced many concerts in different venues.
