Visual archaeology and the cultural archive Magazines like Sounds are primary sources for cultural historians. A PDF preserves not only words but the framing devices — ads for indie labels, tour posters, letters pages — which reveal the industry’s ecosystem: who paid to advertise, which venues supported scenes, which record stores mattered. Those marginalia matter because they show the circuits of attention. In that way, a PDF becomes a map: follow the ads and you map the economy; follow concert listings and you reconstruct the live geography of an era.