I'm a true-blue boomer (1953 vintage) and I can understand the sentiment and agree with the observation the music we hear in our impressionable adoloscence becomes a time-stamp we rarely escape.

But, I think a strong argument may be made that the true zenith of American musical accomplishment is the injection of African-American influences into all realms of "popular" American music between 1920 - 1970.

I consider the greatest contribution to the world from the US to be American Jazz - the music came out of the African expatriate experience and cross-cultural melding in the deep south.  Blues, honky-tonk, Gershwin, Stephen Foster, Copland, Presley, Fats Domino, Miles, Perkins, Ella, Aretha, Sly, James Brown, Marvin Gaye, Disco, Philly Soul - it just goes on and on. Although I believe it has suffered a horrible decline since the mid-90s and I find recent rap, hip-hop, and urban idioms to be a pale shadow of what came before.  I am not sure if that is me being nostalgic and close-minded or a real ( and hopefully temporary) gap.