[beat]

Popular isn't the same as influential. For a good example of "unparalleled influence", look at the Velvet Underground. They hardly sold any copies of their first album, but as (I think) Brian Eno observed, "Everyone who bought that album started a band". Velvet Underground and Nico is arguably one of the ten most important rock albums ever made.

Maybe, fifty years from now, we'll look back on that first Taylor Swift album as world-changing. But I doubt it. Talented? Yes, remarkably so. But I don't hear a "Heroin" or "Venus in Furs" level change in the very nature of music there.