Madonna's debut album was a foundational moment for popular music. Released in 1983, it stands at the turning point between the '70s and '80s, functioning as a kind of gateway drug between disco and synth-driven dance pop. It also stands at the crossroads where the various strains of '80s pop culture met: New Wave, freestyle, R&B and dance pop (often drawn from gay and African American communities) cut through with pop-ified punk aesthetics, the excess of the late '70s and the material girlishness of the '80s -- all taboo-challenging material in an era of increasingly conservative politics. No, seriously, that's all there in "Borderline."
Beyond its sociocultural impact, however, Madonna was also foundational for the lady herself, of course. Not only was it her debut full-length, it was an introduction to her persona: a stubbornly ambitious (and, yes, fairly cocky) artist who wasn't afraid to keep pushing until her ideas took hold in (or perhaps got a choke hold on) American pop culture. A voracious cultural consumer with her finger on the pulse of hot and just-under-the-radar trends (and no shame about reclaiming those trends as her own). A dynamic performer with more than enough sheer persona to balance out her sweet but limited voice. A singer who wanted to get her audience dancing. A woman both poised to be massively well known and constantly on the verge of reinventing herself (by the time of her debut, she'd already tried on "dancer," "club siren" and "New Wave-ish hipster" personas.