How did music affect the Americans in the 1920's?

I'd agree generally with the above posts.  The music of the 20s was indeed a reflection of a more carefree time, when the economy was booming, drinking was against the law and there was enough of a middle class to consider things like leisure activities.  What Jazz did, in my opinion, was reinforce some Americans' wilder side, encouraging them to embrace the rebellious side of themselves and society and enjoy life to the fullest while it lasted.

It's also historically true that a society is generally more creatively and musically expressive during good economic times.  Certainly the 1920s were no exception and jazz is an example.