Omitting jazz from the list of African-American musical innovations is like omitting goal-scoring from Messi's achievements or MacOS from Apple's.

Also, by "rap" I think you mean 'hip-hop', which includes sampling and mixing, especially using turntables.

> Well, blues is the son of jazz music :)

Try some Muddy Waters and John Coltrane, listen, then report back.

With due respect, beyond every form of music being related to every other (just like you are probably a distant relative of mine), they are such different genres that my impression of the comment - which could be completely wrong - is that the commenter has not listed to jazz, blues, or both.