How are blues music and rock and roll music similar?

AnswerYour question poses a double entendre. Blues is the earliest form of Jazz followed by Dixieland, Swing and Modern or Contemporary Jazz.

-----------------------------------------------------------------------------------------------

Actually it depends on witch person you speak with. I believe that the Blues came out of jazz. These music styles have influenced each other through today. They both contain one big component, improvisation. Over the course of a song, one musician seems to spin of on a lead track. this may have been the first time this "element" was introduced to American music.